import java.util.*;
import java.io.*;
import java.math.*;
 
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int ans = 1000 * (x / 500);
        x %= 500;
        ans += 5 * (x / 5);
        System.out.println(ans);
    }

} import java.util.*; util.* java import java.io.*; io.* java import java.math.*; math.* java public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int ans = 1000 * (x / 500);
        x %= 500;
        ans += 5 * (x / 5);
        System.out.println(ans);
    }

} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int ans = 1000 * (x / 500);
        x %= 500;
        ans += 5 * (x / 5);
        System.out.println(ans);
    } main {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int ans = 1000 * (x / 500);
        x %= 500;
        ans += 5 * (x / 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 = 1000 * (x / 500); ans 1000 * (x / 500) 1000 (x / 500) x 500 x %= 500 x 500 ans += 5 * (x / 5) ans 5 * (x / 5) 5 (x / 5) x 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) throws Exception {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int ans = 1000 * (x / 500);
        x %= 500;
        ans += 5 * (x / 5);
        System.out.println(ans);
    }

} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int ans = 1000 * (x / 500);
        x %= 500;
        ans += 5 * (x / 5);
        System.out.println(ans);
    }

} Main
import java.util.*;
import java.io.*;
import java.math.*;
 
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int ans = 1000 * (x / 500);
        x %= 500;
        ans += 5 * (x / 5);
        System.out.println(ans);
    }

}