import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();
        int ans = 0;

        while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        }

        System.out.println(ans);
    }
} import java.util.*; util.* java public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();
        int ans = 0;

        while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        }

        System.out.println(ans);
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();
        int ans = 0;

        while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        }

        System.out.println(ans);
    } main {
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();
        int ans = 0;

        while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        }

        System.out.println(ans);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc int ans = 0; ans 0 while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        } x >= 5 x 5 {
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        } if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            } x >= 500 x 500 {
                x -= 500;
                ans += 1000;
            } x -= 500 x 500 ans += 1000 ans 1000 {
                x -= 5;
                ans += 5;
            } x -= 5 x 5 ans += 5 ans 5 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();
        int ans = 0;

        while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        }

        System.out.println(ans);
    }
} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();
        int ans = 0;

        while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        }

        System.out.println(ans);
    }
} Main
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();
        int ans = 0;

        while(x >= 5){
            if(x >= 500){
                x -= 500;
                ans += 1000;
            }else{
                x -= 5;
                ans += 5;
            }
        }

        System.out.println(ans);
    }
}
