import java.io.*;
// import java.math.*;
import java.util.*;
// import java.util.Map.*;
// import java.util.stream.*;

public class Main {
    public static void main (String[] args) throws IOException {
        final long INF =(long)1e18;
        FastScanner sc = new FastScanner();
        final int N = sc.nextInt();
        long[] A = sc.longArray (N);
        Arrays.sort (A);
        if (A[0] == 0L) {
            System.out.println (0);
            return;
        }
        long ans = 1;
        for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        }
        System.out.println (ans);
        return;
    }

    // FastScanner start
    static class FastScanner {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastScanner() {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public FastScanner (String file_name) throws IOException {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        public char nextChar() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        }

        public String nextString() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        }

        public int[] intArray (int n) throws IOException {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        public long[] longArray (int n) throws IOException {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        }

        public double[] doubleArray (int n) throws IOException {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        }
    }
    // FastScanner end
} import java.io.*; io.* java import java.util.*; util.* java public class Main {
    public static void main (String[] args) throws IOException {
        final long INF =(long)1e18;
        FastScanner sc = new FastScanner();
        final int N = sc.nextInt();
        long[] A = sc.longArray (N);
        Arrays.sort (A);
        if (A[0] == 0L) {
            System.out.println (0);
            return;
        }
        long ans = 1;
        for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        }
        System.out.println (ans);
        return;
    }

    // FastScanner start
    static class FastScanner {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastScanner() {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public FastScanner (String file_name) throws IOException {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        public char nextChar() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        }

        public String nextString() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        }

        public int[] intArray (int n) throws IOException {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        public long[] longArray (int n) throws IOException {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        }

        public double[] doubleArray (int n) throws IOException {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        }
    }
    // FastScanner end
} Main public static void main (String[] args) throws IOException {
        final long INF =(long)1e18;
        FastScanner sc = new FastScanner();
        final int N = sc.nextInt();
        long[] A = sc.longArray (N);
        Arrays.sort (A);
        if (A[0] == 0L) {
            System.out.println (0);
            return;
        }
        long ans = 1;
        for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        }
        System.out.println (ans);
        return;
    } main {
        final long INF =(long)1e18;
        FastScanner sc = new FastScanner();
        final int N = sc.nextInt();
        long[] A = sc.longArray (N);
        Arrays.sort (A);
        if (A[0] == 0L) {
            System.out.println (0);
            return;
        }
        long ans = 1;
        for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        }
        System.out.println (ans);
        return;
    } final long INF =(long)1e18; INF (long)1e18 FastScanner sc = new FastScanner(); sc new FastScanner() final int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc long[] A = sc.longArray (N); A sc.longArray (N) sc.longArray sc N Arrays.sort (A) Arrays.sort Arrays A if (A[0] == 0L) {
            System.out.println (0);
            return;
        } A[0] == 0L A[0] A 0 0L {
            System.out.println (0);
            return;
        } System.out.println (0) System.out.println System.out System System.out 0 return; long ans = 1; ans 1 for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        } long Ai A {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        } {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        } if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            } INF / ans < Ai INF / ans INF ans Ai {
                System.out.println (-1);
                return;
            } System.out.println (-1) System.out.println System.out System System.out -1 1 return; {
                ans *= Ai;
            } ans *= Ai ans Ai System.out.println (ans) System.out.println System.out System System.out ans return; String[] args args static class FastScanner {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastScanner() {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public FastScanner (String file_name) throws IOException {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        public char nextChar() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        }

        public String nextString() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        }

        public int[] intArray (int n) throws IOException {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        public long[] longArray (int n) throws IOException {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        }

        public double[] doubleArray (int n) throws IOException {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        }
    } FastScanner final private int BUFFER_SIZE = 1 << 16; BUFFER_SIZE 1 << 16 1 16 private DataInputStream din; din private byte[] buffer; buffer private int bufferPointer bufferPointer bytesRead; bytesRead public FastScanner() {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        } FastScanner {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        } din = new DataInputStream (System.in) din new DataInputStream (System.in) buffer = new byte[BUFFER_SIZE] buffer new byte[BUFFER_SIZE] BUFFER_SIZE bufferPointer = bytesRead = 0 bufferPointer bytesRead = 0 bytesRead 0 public FastScanner (String file_name) throws IOException {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        } FastScanner {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        } din = new DataInputStream (new FileInputStream (file_name)) din new DataInputStream (new FileInputStream (file_name)) buffer = new byte[BUFFER_SIZE] buffer new byte[BUFFER_SIZE] BUFFER_SIZE bufferPointer = bytesRead = 0 bufferPointer bytesRead = 0 bytesRead 0 String file_name file_name private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        } read {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        } if (bufferPointer == bytesRead)
                fillBuffer(); bufferPointer == bytesRead bufferPointer bytesRead fillBuffer() fillBuffer return buffer[bufferPointer++]; buffer[bufferPointer++] buffer bufferPointer++ bufferPointer public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        } close {
            if (din == null)
                return;
            din.close();
        } if (din == null)
                return; din == null din null return; din.close() din.close din private void fillBuffer() throws IOException {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        } fillBuffer {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        } bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE) bytesRead din.read (buffer, bufferPointer = 0, BUFFER_SIZE) din.read din buffer bufferPointer = 0 bufferPointer 0 BUFFER_SIZE if (bytesRead == -1)
                buffer[0] = -1; bytesRead == -1 bytesRead -1 1 buffer[0] = -1 buffer[0] buffer 0 -1 1 public char nextChar() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        } nextChar {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        } byte c = read(); c read() read while (Character.isWhitespace (c)) {
                c = read();
            } Character.isWhitespace (c) Character.isWhitespace Character c {
                c = read();
            } c = read() c read() read return (char)c; (char)c public String nextString() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        } nextString {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        } byte c = read(); c read() read while (Character.isWhitespace (c)) {
                c = read();
            } Character.isWhitespace (c) Character.isWhitespace Character c {
                c = read();
            } c = read() c read() read StringBuilder builder = new StringBuilder(); builder new StringBuilder() builder.append ((char)c) builder.append builder (char)c c = read() c read() read while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            } !Character.isWhitespace (c) Character.isWhitespace (c) Character.isWhitespace Character c {
                builder.append ((char)c);
                c = read();
            } builder.append ((char)c) builder.append builder (char)c c = read() c read() read return builder.toString(); builder.toString() builder.toString builder public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        } nextInt {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        } int ret = 0; ret 0 byte c = read(); c read() read while (c <= ' ')
                c = read(); c <= ' ' c ' ' c = read() c read() read boolean neg = (c == '-'); neg (c == '-') c '-' if (neg)
                c = read(); neg c = read() c read() read do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9'); (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' {
                ret = ret * 10 + c - '0';
            } ret = ret * 10 + c - '0' ret ret * 10 + c - '0' ret * 10 + c ret * 10 ret 10 c '0' if (neg)
                return -ret; neg return -ret; -ret ret return ret; ret public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        } nextLong {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        } long ret = 0; ret 0 byte c = read(); c read() read while (c <= ' ')
                c = read(); c <= ' ' c ' ' c = read() c read() read boolean neg = (c == '-'); neg (c == '-') c '-' if (neg)
                c = read(); neg c = read() c read() read do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9'); (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' {
                ret = ret * 10 + c - '0';
            } ret = ret * 10 + c - '0' ret ret * 10 + c - '0' ret * 10 + c ret * 10 ret 10 c '0' if (neg)
                return -ret; neg return -ret; -ret ret return ret; ret public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        } nextDouble {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        } double ret = 0 ret 0 div = 1; div 1 byte c = read(); c read() read while (c <= ' ')
                c = read(); c <= ' ' c ' ' c = read() c read() read boolean neg = (c == '-'); neg (c == '-') c '-' if (neg)
                c = read(); neg c = read() c read() read do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9'); (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' {
                ret = ret * 10 + c - '0';
            } ret = ret * 10 + c - '0' ret ret * 10 + c - '0' ret * 10 + c ret * 10 ret 10 c '0' if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            } c == '.' c '.' {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            } while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                } (c = read()) >= '0' && c <= '9' (c = read()) >= '0' (c = read()) c read() read '0' c <= '9' c '9' {
                    ret += (c - '0') / (div *= 10);
                } ret += (c - '0') / (div *= 10) ret (c - '0') / (div *= 10) (c - '0') c '0' (div *= 10) div 10 if (neg)
                return -ret; neg return -ret; -ret ret return ret; ret public int[] intArray (int n) throws IOException {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        } intArray {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        } int arr[] = new int[n]; arr new int[n] n for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                arr[i] = nextInt();
            } {
                arr[i] = nextInt();
            } arr[i] = nextInt() arr[i] arr i nextInt() nextInt return arr; arr int n n public long[] longArray (int n) throws IOException {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        } longArray {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        } long arr[] = new long[n]; arr new long[n] n for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                arr[i] = nextLong();
            } {
                arr[i] = nextLong();
            } arr[i] = nextLong() arr[i] arr i nextLong() nextLong return arr; arr int n n public double[] doubleArray (int n) throws IOException {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        } doubleArray {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        } double arr[] = new double[n]; arr new double[n] n for (int i = 0; i < n; i++)
                arr[i] = nextDouble(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i arr[i] = nextDouble(); arr[i] = nextDouble() arr[i] arr i nextDouble() nextDouble return arr; arr int n n public class Main {
    public static void main (String[] args) throws IOException {
        final long INF =(long)1e18;
        FastScanner sc = new FastScanner();
        final int N = sc.nextInt();
        long[] A = sc.longArray (N);
        Arrays.sort (A);
        if (A[0] == 0L) {
            System.out.println (0);
            return;
        }
        long ans = 1;
        for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        }
        System.out.println (ans);
        return;
    }

    // FastScanner start
    static class FastScanner {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastScanner() {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public FastScanner (String file_name) throws IOException {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        public char nextChar() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        }

        public String nextString() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        }

        public int[] intArray (int n) throws IOException {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        public long[] longArray (int n) throws IOException {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        }

        public double[] doubleArray (int n) throws IOException {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        }
    }
    // FastScanner end
} public class Main {
    public static void main (String[] args) throws IOException {
        final long INF =(long)1e18;
        FastScanner sc = new FastScanner();
        final int N = sc.nextInt();
        long[] A = sc.longArray (N);
        Arrays.sort (A);
        if (A[0] == 0L) {
            System.out.println (0);
            return;
        }
        long ans = 1;
        for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        }
        System.out.println (ans);
        return;
    }

    // FastScanner start
    static class FastScanner {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastScanner() {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public FastScanner (String file_name) throws IOException {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        public char nextChar() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        }

        public String nextString() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        }

        public int[] intArray (int n) throws IOException {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        public long[] longArray (int n) throws IOException {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        }

        public double[] doubleArray (int n) throws IOException {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        }
    }
    // FastScanner end
} Main
import java.io.*;
// import java.math.*;
import java.util.*;
// import java.util.Map.*;
// import java.util.stream.*;

public class Main {
    public static void main (String[] args) throws IOException {
        final long INF =(long)1e18;
        FastScanner sc = new FastScanner();
        final int N = sc.nextInt();
        long[] A = sc.longArray (N);
        Arrays.sort (A);
        if (A[0] == 0L) {
            System.out.println (0);
            return;
        }
        long ans = 1;
        for (long Ai : A) {
            if (INF / ans < Ai) {
                System.out.println (-1);
                return;
            } else {
                ans *= Ai;
            }
        }
        System.out.println (ans);
        return;
    }

    // FastScanner start
    static class FastScanner {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public FastScanner() {
            din = new DataInputStream (System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public FastScanner (String file_name) throws IOException {
            din = new DataInputStream (new FileInputStream (file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        private byte read() throws IOException {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException {
            if (din == null)
                return;
            din.close();
        }

        private void fillBuffer() throws IOException {
            bytesRead = din.read (buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        public char nextChar() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            return (char)c;
        }

        public String nextString() throws IOException {
            byte c = read();
            while (Character.isWhitespace (c)) {
                c = read();
            }
            StringBuilder builder = new StringBuilder();
            builder.append ((char)c);
            c = read();
            while (!Character.isWhitespace (c)) {
                builder.append ((char)c);
                c = read();
            }
            return builder.toString();
        }

        public int nextInt() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
            if (neg)
                return -ret;
            return ret;
        }

        public int[] intArray (int n) throws IOException {
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextInt();
            }
            return arr;
        }

        public long[] longArray (int n) throws IOException {
            long arr[] = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLong();
            }
            return arr;
        }

        public double[] doubleArray (int n) throws IOException {
            double arr[] = new double[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextDouble();
            return arr;
        }
    }
    // FastScanner end
}
