import java.io.*;
import java.util.*;
/**
 * Main
 */
public class Main {
       static int mod  = 1000000007;
        static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) {
       MyScanner ms  = new MyScanner();
        long n= ms.nextInt();
        int [] yen = {500,5};
        long sum=0;
        for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        }
        pw.println(sum);
    pw.flush();

    }public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
   
        public MyScanner() {
           br = new BufferedReader(new InputStreamReader(System.in));
        }
   
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
   
        int nextInt() {
            return Integer.parseInt(next());
        }
   
        long nextLong() {
            return Long.parseLong(next());
        }
   
        double nextDouble() {
            return Double.parseDouble(next());
        }
   
        String nextLine(){
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        }
  
     }
} import java.io.*; io.* java import java.util.*; util.* java public class Main {
       static int mod  = 1000000007;
        static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) {
       MyScanner ms  = new MyScanner();
        long n= ms.nextInt();
        int [] yen = {500,5};
        long sum=0;
        for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        }
        pw.println(sum);
    pw.flush();

    }public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
   
        public MyScanner() {
           br = new BufferedReader(new InputStreamReader(System.in));
        }
   
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
   
        int nextInt() {
            return Integer.parseInt(next());
        }
   
        long nextLong() {
            return Long.parseLong(next());
        }
   
        double nextDouble() {
            return Double.parseDouble(next());
        }
   
        String nextLine(){
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        }
  
     }
} Main static int mod  = 1000000007; mod 1000000007 static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out)); pw new PrintWriter(new OutputStreamWriter(System.out)) public static void main(String[] args) {
       MyScanner ms  = new MyScanner();
        long n= ms.nextInt();
        int [] yen = {500,5};
        long sum=0;
        for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        }
        pw.println(sum);
    pw.flush();

    } main {
       MyScanner ms  = new MyScanner();
        long n= ms.nextInt();
        int [] yen = {500,5};
        long sum=0;
        for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        }
        pw.println(sum);
    pw.flush();

    } MyScanner ms  = new MyScanner(); ms new MyScanner() long n= ms.nextInt(); n ms.nextInt() ms.nextInt ms int [] yen = {500,5}; yen {500,5} 500 5 long sum=0; sum 0 for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        } int i=0; int i=0; i 0 i<yen.length i yen.length yen yen.length i++ i++ i {
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        } {
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        } while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                } yen[i]<=n yen[i] yen i n {
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                } if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5; yen[i]==500 yen[i] yen i 500 sum+=1000 sum 1000 if(yen[i]==5)
                    sum+=5; yen[i]==5 yen[i] yen i 5 sum+=5 sum 5 n-=yen[i] n yen[i] yen i pw.println(sum) pw.println pw sum pw.flush() pw.flush pw String[] args args public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
   
        public MyScanner() {
           br = new BufferedReader(new InputStreamReader(System.in));
        }
   
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
   
        int nextInt() {
            return Integer.parseInt(next());
        }
   
        long nextLong() {
            return Long.parseLong(next());
        }
   
        double nextDouble() {
            return Double.parseDouble(next());
        }
   
        String nextLine(){
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        }
  
     } MyScanner BufferedReader br; br StringTokenizer st; st public MyScanner() {
           br = new BufferedReader(new InputStreamReader(System.in));
        } MyScanner {
           br = new BufferedReader(new InputStreamReader(System.in));
        } br = new BufferedReader(new InputStreamReader(System.in)) br new BufferedReader(new InputStreamReader(System.in)) String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } next {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } st == null || !st.hasMoreElements() st == null st null !st.hasMoreElements() st.hasMoreElements() st.hasMoreElements st {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } IOException e {
                    e.printStackTrace();
                } e.printStackTrace() e.printStackTrace e {
                    st = new StringTokenizer(br.readLine());
                } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st int nextInt() {
            return Integer.parseInt(next());
        } nextInt {
            return Integer.parseInt(next());
        } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next long nextLong() {
            return Long.parseLong(next());
        } nextLong {
            return Long.parseLong(next());
        } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next double nextDouble() {
            return Double.parseDouble(next());
        } nextDouble {
            return Double.parseDouble(next());
        } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next String nextLine(){
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        } nextLine {
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        } String str = ""; str "" try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        } catch (IOException e) {
           e.printStackTrace();
        } IOException e {
           e.printStackTrace();
        } e.printStackTrace() e.printStackTrace e {
           str = br.readLine();
        } str = br.readLine() str br.readLine() br.readLine br return str; str public class Main {
       static int mod  = 1000000007;
        static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) {
       MyScanner ms  = new MyScanner();
        long n= ms.nextInt();
        int [] yen = {500,5};
        long sum=0;
        for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        }
        pw.println(sum);
    pw.flush();

    }public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
   
        public MyScanner() {
           br = new BufferedReader(new InputStreamReader(System.in));
        }
   
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
   
        int nextInt() {
            return Integer.parseInt(next());
        }
   
        long nextLong() {
            return Long.parseLong(next());
        }
   
        double nextDouble() {
            return Double.parseDouble(next());
        }
   
        String nextLine(){
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        }
  
     }
} public class Main {
       static int mod  = 1000000007;
        static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) {
       MyScanner ms  = new MyScanner();
        long n= ms.nextInt();
        int [] yen = {500,5};
        long sum=0;
        for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        }
        pw.println(sum);
    pw.flush();

    }public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
   
        public MyScanner() {
           br = new BufferedReader(new InputStreamReader(System.in));
        }
   
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
   
        int nextInt() {
            return Integer.parseInt(next());
        }
   
        long nextLong() {
            return Long.parseLong(next());
        }
   
        double nextDouble() {
            return Double.parseDouble(next());
        }
   
        String nextLine(){
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        }
  
     }
} Main
import java.io.*;
import java.util.*;
/**
 * Main
 */
public class Main {
       static int mod  = 1000000007;
        static PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) {
       MyScanner ms  = new MyScanner();
        long n= ms.nextInt();
        int [] yen = {500,5};
        long sum=0;
        for(int i=0;i<yen.length;i++){
                while(yen[i]<=n){
                  if(yen[i]==500)
                  sum+=1000;
                  else if(yen[i]==5)
                    sum+=5;
                  n-=yen[i];
                }
        }
        pw.println(sum);
    pw.flush();

    }public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
   
        public MyScanner() {
           br = new BufferedReader(new InputStreamReader(System.in));
        }
   
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
   
        int nextInt() {
            return Integer.parseInt(next());
        }
   
        long nextLong() {
            return Long.parseLong(next());
        }
   
        double nextDouble() {
            return Double.parseDouble(next());
        }
   
        String nextLine(){
            String str = "";
        try {
           str = br.readLine();
        } catch (IOException e) {
           e.printStackTrace();
        }
        return str;
        }
  
     }
}