import java.text.DecimalFormat;
import java.util.stream.LongStream;
import java.util.stream.IntStream;
import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
       // int t = sc.nextInt();
       // while(t-->0){
        Naveen problem = new Naveen(sc);
            problem.solve(out);
       // }
        out.flush();
    }

}

class Naveen {

    long a,b,c,d;
    //int[]  arr;
    

    Naveen(FastScanner sc) {
    
         a = sc.nextLong();
         b = sc.nextLong();
         c = sc.nextLong();
         d = sc.nextLong();
       //  arr = sc.arrayInt(n);
    }

    void solve(PrintWriter out) {
      
        long arr[]=new long[4];

    arr[0]=a*c;
    arr[1]=a*d;
    arr[2]=b*c;
    arr[3]=b*d;
    Arrays.sort(arr);
    out.println(arr[3]);
    }

   
}

class FastScanner {

    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }

    private int readByte() {
        if (hasNextByte()) {
            return buffer[ptr++];
        } else {
            return -1;
        }
    }

    private static boolean isPrintableChar(int c) {
        return 33 <= c && c <= 126;
    }

    public boolean hasNext() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++;
        }
        return hasNextByte();
    }

    public String next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }

    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
            throw new NumberFormatException();
        }
        return (int) nl;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public int[] arrayInt(int N) {
        int[] array = new int[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextInt();
        }
        return array;
    }

    public long[] arrayLong(int N) {
        long[] array = new long[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextLong();
        }
        return array;
    }

    public double[] arrayDouble(int N) {
        double[] array = new double[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextDouble();
        }
        return array;
    }

    public String[] arrayString(int N) {
        String[] array = new String[N];
        for (int i = 0; i < N; i++) {
            array[i] = next();
        }
        return array;
    }

    public int randomInt() {
        Random r = new Random();
        int value = r.nextInt((int) 1e6);
        System.out.println(value);
        return value;
    }

    public int[] randomInt(int N) {
        int[] array = new int[N];
        Random r = new Random();
        for (int i = 0; i < N; i++) {
            array[i] = r.nextInt((int) 1e6);
        }
        System.out.println(Arrays.toString(array));
        return array;
    }

}

class My {

  public static long lower(long arr[],long key){
        int low = 0;
        int high = arr.length-1;
        while(low < high){
            int mid = low + (high - low)/2;
            if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            }
        }
        return low;
    }
public static int upper(int arr[],int key){
    int low = 0;
    int high = arr.length-1;
    while(low < high){
        int mid = low + (high - low+1)/2;
        if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        }
    }
    return low;
}
    static void ans(boolean b) {
        System.out.println(b ? "Yes" : "No");
    }

    static void ANS(boolean b) {
        System.out.println(b ? "YES" : "NO");
    }

    static String sort(String s) {
        char[] ch = s.toCharArray();
        Arrays.sort(ch);
        return String.valueOf(ch);
    }

    static String reverse(String s) {
        return new StringBuilder(s).reverse().toString();
    }

    static int[] reverse(int[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static long[] reverse(long[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static double[] reverse(double[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static String[] reverse(String[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static char[] reverse(char[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static long min(long... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static int min(int... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static double min(double... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static long max(long... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static int max(int... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static double max(double... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static int sum(long number) {
        int sum = 0;
        while (number > 0) {
            sum += number % 10;
            number /= 10;
        }
        return sum;
    }

} import java.text.DecimalFormat; DecimalFormat java.text import java.util.stream.LongStream; LongStream java.util.stream import java.util.stream.IntStream; IntStream java.util.stream import java.io.*; io.* java import java.util.*; util.* java public class Main {

    public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
       // int t = sc.nextInt();
       // while(t-->0){
        Naveen problem = new Naveen(sc);
            problem.solve(out);
       // }
        out.flush();
    }

} Main public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
       // int t = sc.nextInt();
       // while(t-->0){
        Naveen problem = new Naveen(sc);
            problem.solve(out);
       // }
        out.flush();
    } main {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
       // int t = sc.nextInt();
       // while(t-->0){
        Naveen problem = new Naveen(sc);
            problem.solve(out);
       // }
        out.flush();
    } FastScanner sc = new FastScanner(); sc new FastScanner() PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) Naveen problem = new Naveen(sc); problem new Naveen(sc) problem.solve(out) problem.solve problem out out.flush() out.flush out String[] args args class Naveen {

    long a,b,c,d;
    //int[]  arr;
    

    Naveen(FastScanner sc) {
    
         a = sc.nextLong();
         b = sc.nextLong();
         c = sc.nextLong();
         d = sc.nextLong();
       //  arr = sc.arrayInt(n);
    }

    void solve(PrintWriter out) {
      
        long arr[]=new long[4];

    arr[0]=a*c;
    arr[1]=a*d;
    arr[2]=b*c;
    arr[3]=b*d;
    Arrays.sort(arr);
    out.println(arr[3]);
    }

   
} Naveen long a a b b c c d; d Naveen(FastScanner sc) {
    
         a = sc.nextLong();
         b = sc.nextLong();
         c = sc.nextLong();
         d = sc.nextLong();
       //  arr = sc.arrayInt(n);
    } Naveen {
    
         a = sc.nextLong();
         b = sc.nextLong();
         c = sc.nextLong();
         d = sc.nextLong();
       //  arr = sc.arrayInt(n);
    } a = sc.nextLong() a sc.nextLong() sc.nextLong sc b = sc.nextLong() b sc.nextLong() sc.nextLong sc c = sc.nextLong() c sc.nextLong() sc.nextLong sc d = sc.nextLong() d sc.nextLong() sc.nextLong sc FastScanner sc sc void solve(PrintWriter out) {
      
        long arr[]=new long[4];

    arr[0]=a*c;
    arr[1]=a*d;
    arr[2]=b*c;
    arr[3]=b*d;
    Arrays.sort(arr);
    out.println(arr[3]);
    } solve {
      
        long arr[]=new long[4];

    arr[0]=a*c;
    arr[1]=a*d;
    arr[2]=b*c;
    arr[3]=b*d;
    Arrays.sort(arr);
    out.println(arr[3]);
    } long arr[]=new long[4]; arr new long[4] 4 arr[0]=a*c arr[0] arr 0 a*c a c arr[1]=a*d arr[1] arr 1 a*d a d arr[2]=b*c arr[2] arr 2 b*c b c arr[3]=b*d arr[3] arr 3 b*d b d Arrays.sort(arr) Arrays.sort Arrays arr out.println(arr[3]) out.println out arr[3] arr 3 PrintWriter out out class FastScanner {

    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }

    private int readByte() {
        if (hasNextByte()) {
            return buffer[ptr++];
        } else {
            return -1;
        }
    }

    private static boolean isPrintableChar(int c) {
        return 33 <= c && c <= 126;
    }

    public boolean hasNext() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++;
        }
        return hasNextByte();
    }

    public String next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }

    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
            throw new NumberFormatException();
        }
        return (int) nl;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public int[] arrayInt(int N) {
        int[] array = new int[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextInt();
        }
        return array;
    }

    public long[] arrayLong(int N) {
        long[] array = new long[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextLong();
        }
        return array;
    }

    public double[] arrayDouble(int N) {
        double[] array = new double[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextDouble();
        }
        return array;
    }

    public String[] arrayString(int N) {
        String[] array = new String[N];
        for (int i = 0; i < N; i++) {
            array[i] = next();
        }
        return array;
    }

    public int randomInt() {
        Random r = new Random();
        int value = r.nextInt((int) 1e6);
        System.out.println(value);
        return value;
    }

    public int[] randomInt(int N) {
        int[] array = new int[N];
        Random r = new Random();
        for (int i = 0; i < N; i++) {
            array[i] = r.nextInt((int) 1e6);
        }
        System.out.println(Arrays.toString(array));
        return array;
    }

} FastScanner private final InputStream in = System.in; in System.in System System.in private final byte[] buffer = new byte[1024]; buffer new byte[1024] 1024 private int ptr = 0; ptr 0 private int buflen = 0; buflen 0 private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    } hasNextByte {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    } if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        } ptr < buflen ptr buflen {
            return true;
        } return true; true {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        } ptr = 0 ptr 0 try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } IOException e {
                e.printStackTrace();
            } e.printStackTrace() e.printStackTrace e {
                buflen = in.read(buffer);
            } buflen = in.read(buffer) buflen in.read(buffer) in.read in buffer if (buflen <= 0) {
                return false;
            } buflen <= 0 buflen 0 {
                return false;
            } return false; false return true; true private int readByte() {
        if (hasNextByte()) {
            return buffer[ptr++];
        } else {
            return -1;
        }
    } readByte {
        if (hasNextByte()) {
            return buffer[ptr++];
        } else {
            return -1;
        }
    } if (hasNextByte()) {
            return buffer[ptr++];
        } else {
            return -1;
        } hasNextByte() hasNextByte {
            return buffer[ptr++];
        } return buffer[ptr++]; buffer[ptr++] buffer ptr++ ptr {
            return -1;
        } return -1; -1 1 private static boolean isPrintableChar(int c) {
        return 33 <= c && c <= 126;
    } isPrintableChar {
        return 33 <= c && c <= 126;
    } return 33 <= c && c <= 126; 33 <= c && c <= 126 33 <= c 33 c c <= 126 c 126 int c c public boolean hasNext() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++;
        }
        return hasNextByte();
    } hasNext {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++;
        }
        return hasNextByte();
    } while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++;
        } hasNextByte() && !isPrintableChar(buffer[ptr]) hasNextByte() hasNextByte !isPrintableChar(buffer[ptr]) isPrintableChar(buffer[ptr]) isPrintableChar buffer[ptr] buffer ptr {
            ptr++;
        } ptr++ ptr return hasNextByte(); hasNextByte() hasNextByte public String next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    } next {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    } if (!hasNext()) {
            throw new NoSuchElementException();
        } !hasNext() hasNext() hasNext {
            throw new NoSuchElementException();
        } throw new NoSuchElementException(); new NoSuchElementException() StringBuilder sb = new StringBuilder(); sb new StringBuilder() int b = readByte(); b readByte() readByte while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        } isPrintableChar(b) isPrintableChar b {
            sb.appendCodePoint(b);
            b = readByte();
        } sb.appendCodePoint(b) sb.appendCodePoint sb b b = readByte() b readByte() readByte return sb.toString(); sb.toString() sb.toString sb public long nextLong() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    } nextLong {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    } if (!hasNext()) {
            throw new NoSuchElementException();
        } !hasNext() hasNext() hasNext {
            throw new NoSuchElementException();
        } throw new NoSuchElementException(); new NoSuchElementException() long n = 0; n 0 boolean minus = false; minus false int b = readByte(); b readByte() readByte if (b == '-') {
            minus = true;
            b = readByte();
        } b == '-' b '-' {
            minus = true;
            b = readByte();
        } minus = true minus true b = readByte() b readByte() readByte if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        } b < '0' || '9' < b b < '0' b '0' '9' < b '9' b {
            throw new NumberFormatException();
        } throw new NumberFormatException(); new NumberFormatException() while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        } true {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        } if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            } '0' <= b && b <= '9' '0' <= b '0' b b <= '9' b '9' {
                n *= 10;
                n += b - '0';
            } n *= 10 n 10 n += b - '0' n b - '0' b '0' if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            } b == -1 || !isPrintableChar(b) b == -1 b -1 1 !isPrintableChar(b) isPrintableChar(b) isPrintableChar b {
                return minus ? -n : n;
            } return minus ? -n : n; minus ? -n : n minus -n n n {
                throw new NumberFormatException();
            } throw new NumberFormatException(); new NumberFormatException() b = readByte() b readByte() readByte public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
            throw new NumberFormatException();
        }
        return (int) nl;
    } nextInt {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
            throw new NumberFormatException();
        }
        return (int) nl;
    } long nl = nextLong(); nl nextLong() nextLong if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
            throw new NumberFormatException();
        } nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE nl < Integer.MIN_VALUE nl Integer.MIN_VALUE Integer Integer.MIN_VALUE nl > Integer.MAX_VALUE nl Integer.MAX_VALUE Integer Integer.MAX_VALUE {
            throw new NumberFormatException();
        } throw new NumberFormatException(); new NumberFormatException() return (int) nl; (int) nl public double nextDouble() {
        return Double.parseDouble(next());
    } nextDouble {
        return Double.parseDouble(next());
    } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next public int[] arrayInt(int N) {
        int[] array = new int[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextInt();
        }
        return array;
    } arrayInt {
        int[] array = new int[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextInt();
        }
        return array;
    } int[] array = new int[N]; array new int[N] N for (int i = 0; i < N; i++) {
            array[i] = nextInt();
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            array[i] = nextInt();
        } {
            array[i] = nextInt();
        } array[i] = nextInt() array[i] array i nextInt() nextInt return array; array int N N public long[] arrayLong(int N) {
        long[] array = new long[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextLong();
        }
        return array;
    } arrayLong {
        long[] array = new long[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextLong();
        }
        return array;
    } long[] array = new long[N]; array new long[N] N for (int i = 0; i < N; i++) {
            array[i] = nextLong();
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            array[i] = nextLong();
        } {
            array[i] = nextLong();
        } array[i] = nextLong() array[i] array i nextLong() nextLong return array; array int N N public double[] arrayDouble(int N) {
        double[] array = new double[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextDouble();
        }
        return array;
    } arrayDouble {
        double[] array = new double[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextDouble();
        }
        return array;
    } double[] array = new double[N]; array new double[N] N for (int i = 0; i < N; i++) {
            array[i] = nextDouble();
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            array[i] = nextDouble();
        } {
            array[i] = nextDouble();
        } array[i] = nextDouble() array[i] array i nextDouble() nextDouble return array; array int N N public String[] arrayString(int N) {
        String[] array = new String[N];
        for (int i = 0; i < N; i++) {
            array[i] = next();
        }
        return array;
    } arrayString {
        String[] array = new String[N];
        for (int i = 0; i < N; i++) {
            array[i] = next();
        }
        return array;
    } String[] array = new String[N]; array new String[N] N for (int i = 0; i < N; i++) {
            array[i] = next();
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            array[i] = next();
        } {
            array[i] = next();
        } array[i] = next() array[i] array i next() next return array; array int N N public int randomInt() {
        Random r = new Random();
        int value = r.nextInt((int) 1e6);
        System.out.println(value);
        return value;
    } randomInt {
        Random r = new Random();
        int value = r.nextInt((int) 1e6);
        System.out.println(value);
        return value;
    } Random r = new Random(); r new Random() int value = r.nextInt((int) 1e6); value r.nextInt((int) 1e6) r.nextInt r (int) 1e6 System.out.println(value) System.out.println System.out System System.out value return value; value public int[] randomInt(int N) {
        int[] array = new int[N];
        Random r = new Random();
        for (int i = 0; i < N; i++) {
            array[i] = r.nextInt((int) 1e6);
        }
        System.out.println(Arrays.toString(array));
        return array;
    } randomInt {
        int[] array = new int[N];
        Random r = new Random();
        for (int i = 0; i < N; i++) {
            array[i] = r.nextInt((int) 1e6);
        }
        System.out.println(Arrays.toString(array));
        return array;
    } int[] array = new int[N]; array new int[N] N Random r = new Random(); r new Random() for (int i = 0; i < N; i++) {
            array[i] = r.nextInt((int) 1e6);
        } int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
            array[i] = r.nextInt((int) 1e6);
        } {
            array[i] = r.nextInt((int) 1e6);
        } array[i] = r.nextInt((int) 1e6) array[i] array i r.nextInt((int) 1e6) r.nextInt r (int) 1e6 System.out.println(Arrays.toString(array)) System.out.println System.out System System.out Arrays.toString(array) Arrays.toString Arrays array return array; array int N N class My {

  public static long lower(long arr[],long key){
        int low = 0;
        int high = arr.length-1;
        while(low < high){
            int mid = low + (high - low)/2;
            if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            }
        }
        return low;
    }
public static int upper(int arr[],int key){
    int low = 0;
    int high = arr.length-1;
    while(low < high){
        int mid = low + (high - low+1)/2;
        if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        }
    }
    return low;
}
    static void ans(boolean b) {
        System.out.println(b ? "Yes" : "No");
    }

    static void ANS(boolean b) {
        System.out.println(b ? "YES" : "NO");
    }

    static String sort(String s) {
        char[] ch = s.toCharArray();
        Arrays.sort(ch);
        return String.valueOf(ch);
    }

    static String reverse(String s) {
        return new StringBuilder(s).reverse().toString();
    }

    static int[] reverse(int[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static long[] reverse(long[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static double[] reverse(double[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static String[] reverse(String[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static char[] reverse(char[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static long min(long... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static int min(int... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static double min(double... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static long max(long... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static int max(int... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static double max(double... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static int sum(long number) {
        int sum = 0;
        while (number > 0) {
            sum += number % 10;
            number /= 10;
        }
        return sum;
    }

} My public static long lower(long arr[],long key){
        int low = 0;
        int high = arr.length-1;
        while(low < high){
            int mid = low + (high - low)/2;
            if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            }
        }
        return low;
    } lower {
        int low = 0;
        int high = arr.length-1;
        while(low < high){
            int mid = low + (high - low)/2;
            if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            }
        }
        return low;
    } int low = 0; low 0 int high = arr.length-1; high arr.length-1 arr.length arr arr.length 1 while(low < high){
            int mid = low + (high - low)/2;
            if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            }
        } low < high low high {
            int mid = low + (high - low)/2;
            if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            }
        } int mid = low + (high - low)/2; mid low + (high - low)/2 low (high - low)/2 (high - low) high low 2 if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            } arr[mid] >= key arr[mid] arr mid key {
                high = mid;
            } high = mid high mid {
                low = mid+1;
            } low = mid+1 low mid+1 mid 1 return low; low long arr[] arr long key key public static int upper(int arr[],int key){
    int low = 0;
    int high = arr.length-1;
    while(low < high){
        int mid = low + (high - low+1)/2;
        if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        }
    }
    return low;
} upper {
    int low = 0;
    int high = arr.length-1;
    while(low < high){
        int mid = low + (high - low+1)/2;
        if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        }
    }
    return low;
} int low = 0; low 0 int high = arr.length-1; high arr.length-1 arr.length arr arr.length 1 while(low < high){
        int mid = low + (high - low+1)/2;
        if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        }
    } low < high low high {
        int mid = low + (high - low+1)/2;
        if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        }
    } int mid = low + (high - low+1)/2; mid low + (high - low+1)/2 low (high - low+1)/2 (high - low+1) high - low high low 1 2 if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        } arr[mid] <= key arr[mid] arr mid key {
            low = mid;
        } low = mid low mid {
            high = mid-1;
        } high = mid-1 high mid-1 mid 1 return low; low int arr[] arr int key key static void ans(boolean b) {
        System.out.println(b ? "Yes" : "No");
    } ans {
        System.out.println(b ? "Yes" : "No");
    } System.out.println(b ? "Yes" : "No") System.out.println System.out System System.out b ? "Yes" : "No" b "Yes" "No" boolean b b static void ANS(boolean b) {
        System.out.println(b ? "YES" : "NO");
    } ANS {
        System.out.println(b ? "YES" : "NO");
    } System.out.println(b ? "YES" : "NO") System.out.println System.out System System.out b ? "YES" : "NO" b "YES" "NO" boolean b b static String sort(String s) {
        char[] ch = s.toCharArray();
        Arrays.sort(ch);
        return String.valueOf(ch);
    } sort {
        char[] ch = s.toCharArray();
        Arrays.sort(ch);
        return String.valueOf(ch);
    } char[] ch = s.toCharArray(); ch s.toCharArray() s.toCharArray s Arrays.sort(ch) Arrays.sort Arrays ch return String.valueOf(ch); String.valueOf(ch) String.valueOf String ch String s s static String reverse(String s) {
        return new StringBuilder(s).reverse().toString();
    } reverse {
        return new StringBuilder(s).reverse().toString();
    } return new StringBuilder(s).reverse().toString(); new StringBuilder(s).reverse().toString() new StringBuilder(s).reverse().toString new StringBuilder(s).reverse() new StringBuilder(s).reverse new StringBuilder(s) String s s static int[] reverse(int[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } reverse {
        for (int i = 0; i < array.length / 2; i++) {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } for (int i = 0; i < array.length / 2; i++) {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } int i = 0; int i = 0; i 0 i < array.length / 2 i array.length / 2 array.length array array.length 2 i++ i++ i {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } int temp = array[i]; temp array[i] array i array[i] = array[array.length - 1 - i] array[i] array i array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i array[array.length - 1 - i] = temp array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i temp return array; array int[] array array static long[] reverse(long[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } reverse {
        for (int i = 0; i < array.length / 2; i++) {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } for (int i = 0; i < array.length / 2; i++) {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } int i = 0; int i = 0; i 0 i < array.length / 2 i array.length / 2 array.length array array.length 2 i++ i++ i {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } long temp = array[i]; temp array[i] array i array[i] = array[array.length - 1 - i] array[i] array i array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i array[array.length - 1 - i] = temp array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i temp return array; array long[] array array static double[] reverse(double[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } reverse {
        for (int i = 0; i < array.length / 2; i++) {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } for (int i = 0; i < array.length / 2; i++) {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } int i = 0; int i = 0; i 0 i < array.length / 2 i array.length / 2 array.length array array.length 2 i++ i++ i {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } double temp = array[i]; temp array[i] array i array[i] = array[array.length - 1 - i] array[i] array i array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i array[array.length - 1 - i] = temp array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i temp return array; array double[] array array static String[] reverse(String[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } reverse {
        for (int i = 0; i < array.length / 2; i++) {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } for (int i = 0; i < array.length / 2; i++) {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } int i = 0; int i = 0; i 0 i < array.length / 2 i array.length / 2 array.length array array.length 2 i++ i++ i {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } String temp = array[i]; temp array[i] array i array[i] = array[array.length - 1 - i] array[i] array i array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i array[array.length - 1 - i] = temp array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i temp return array; array String[] array array static char[] reverse(char[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } reverse {
        for (int i = 0; i < array.length / 2; i++) {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    } for (int i = 0; i < array.length / 2; i++) {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } int i = 0; int i = 0; i 0 i < array.length / 2 i array.length / 2 array.length array array.length 2 i++ i++ i {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        } char temp = array[i]; temp array[i] array i array[i] = array[array.length - 1 - i] array[i] array i array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i array[array.length - 1 - i] = temp array[array.length - 1 - i] array array.length - 1 - i array.length - 1 - i array.length array array.length 1 i temp return array; array char[] array array static long min(long... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    } min {
        Arrays.sort(numbers);
        return numbers[0];
    } Arrays.sort(numbers) Arrays.sort Arrays numbers return numbers[0]; numbers[0] numbers 0 long... numbers numbers static int min(int... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    } min {
        Arrays.sort(numbers);
        return numbers[0];
    } Arrays.sort(numbers) Arrays.sort Arrays numbers return numbers[0]; numbers[0] numbers 0 int... numbers numbers static double min(double... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    } min {
        Arrays.sort(numbers);
        return numbers[0];
    } Arrays.sort(numbers) Arrays.sort Arrays numbers return numbers[0]; numbers[0] numbers 0 double... numbers numbers static long max(long... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    } max {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    } Arrays.sort(numbers) Arrays.sort Arrays numbers return numbers[numbers.length - 1]; numbers[numbers.length - 1] numbers numbers.length - 1 numbers.length numbers numbers.length 1 long... numbers numbers static int max(int... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    } max {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    } Arrays.sort(numbers) Arrays.sort Arrays numbers return numbers[numbers.length - 1]; numbers[numbers.length - 1] numbers numbers.length - 1 numbers.length numbers numbers.length 1 int... numbers numbers static double max(double... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    } max {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    } Arrays.sort(numbers) Arrays.sort Arrays numbers return numbers[numbers.length - 1]; numbers[numbers.length - 1] numbers numbers.length - 1 numbers.length numbers numbers.length 1 double... numbers numbers static int sum(long number) {
        int sum = 0;
        while (number > 0) {
            sum += number % 10;
            number /= 10;
        }
        return sum;
    } sum {
        int sum = 0;
        while (number > 0) {
            sum += number % 10;
            number /= 10;
        }
        return sum;
    } int sum = 0; sum 0 while (number > 0) {
            sum += number % 10;
            number /= 10;
        } number > 0 number 0 {
            sum += number % 10;
            number /= 10;
        } sum += number % 10 sum number % 10 number 10 number /= 10 number 10 return sum; sum long number number public class Main {

    public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
       // int t = sc.nextInt();
       // while(t-->0){
        Naveen problem = new Naveen(sc);
            problem.solve(out);
       // }
        out.flush();
    }

} public class Main {

    public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
       // int t = sc.nextInt();
       // while(t-->0){
        Naveen problem = new Naveen(sc);
            problem.solve(out);
       // }
        out.flush();
    }

} Main
import java.text.DecimalFormat;
import java.util.stream.LongStream;
import java.util.stream.IntStream;
import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
       // int t = sc.nextInt();
       // while(t-->0){
        Naveen problem = new Naveen(sc);
            problem.solve(out);
       // }
        out.flush();
    }

}

class Naveen {

    long a,b,c,d;
    //int[]  arr;
    

    Naveen(FastScanner sc) {
    
         a = sc.nextLong();
         b = sc.nextLong();
         c = sc.nextLong();
         d = sc.nextLong();
       //  arr = sc.arrayInt(n);
    }

    void solve(PrintWriter out) {
      
        long arr[]=new long[4];

    arr[0]=a*c;
    arr[1]=a*d;
    arr[2]=b*c;
    arr[3]=b*d;
    Arrays.sort(arr);
    out.println(arr[3]);
    }

   
}

class FastScanner {

    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        } else {
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }

    private int readByte() {
        if (hasNextByte()) {
            return buffer[ptr++];
        } else {
            return -1;
        }
    }

    private static boolean isPrintableChar(int c) {
        return 33 <= c && c <= 126;
    }

    public boolean hasNext() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) {
            ptr++;
        }
        return hasNextByte();
    }

    public String next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while (isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    public long nextLong() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while (true) {
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            } else if (b == -1 || !isPrintableChar(b)) {
                return minus ? -n : n;
            } else {
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }

    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
            throw new NumberFormatException();
        }
        return (int) nl;
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public int[] arrayInt(int N) {
        int[] array = new int[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextInt();
        }
        return array;
    }

    public long[] arrayLong(int N) {
        long[] array = new long[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextLong();
        }
        return array;
    }

    public double[] arrayDouble(int N) {
        double[] array = new double[N];
        for (int i = 0; i < N; i++) {
            array[i] = nextDouble();
        }
        return array;
    }

    public String[] arrayString(int N) {
        String[] array = new String[N];
        for (int i = 0; i < N; i++) {
            array[i] = next();
        }
        return array;
    }

    public int randomInt() {
        Random r = new Random();
        int value = r.nextInt((int) 1e6);
        System.out.println(value);
        return value;
    }

    public int[] randomInt(int N) {
        int[] array = new int[N];
        Random r = new Random();
        for (int i = 0; i < N; i++) {
            array[i] = r.nextInt((int) 1e6);
        }
        System.out.println(Arrays.toString(array));
        return array;
    }

}

class My {

  public static long lower(long arr[],long key){
        int low = 0;
        int high = arr.length-1;
        while(low < high){
            int mid = low + (high - low)/2;
            if(arr[mid] >= key){
                high = mid;
            }
            else{
                low = mid+1;
            }
        }
        return low;
    }
public static int upper(int arr[],int key){
    int low = 0;
    int high = arr.length-1;
    while(low < high){
        int mid = low + (high - low+1)/2;
        if(arr[mid] <= key){
            low = mid;
        }
        else{
            high = mid-1;
        }
    }
    return low;
}
    static void ans(boolean b) {
        System.out.println(b ? "Yes" : "No");
    }

    static void ANS(boolean b) {
        System.out.println(b ? "YES" : "NO");
    }

    static String sort(String s) {
        char[] ch = s.toCharArray();
        Arrays.sort(ch);
        return String.valueOf(ch);
    }

    static String reverse(String s) {
        return new StringBuilder(s).reverse().toString();
    }

    static int[] reverse(int[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            int temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static long[] reverse(long[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            long temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static double[] reverse(double[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            double temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static String[] reverse(String[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            String temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static char[] reverse(char[] array) {
        for (int i = 0; i < array.length / 2; i++) {
            char temp = array[i];
            array[i] = array[array.length - 1 - i];
            array[array.length - 1 - i] = temp;
        }
        return array;
    }

    static long min(long... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static int min(int... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static double min(double... numbers) {
        Arrays.sort(numbers);
        return numbers[0];
    }

    static long max(long... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static int max(int... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static double max(double... numbers) {
        Arrays.sort(numbers);
        return numbers[numbers.length - 1];
    }

    static int sum(long number) {
        int sum = 0;
        while (number > 0) {
            sum += number % 10;
            number /= 10;
        }
        return sum;
    }

}
