import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        
        int happy = 0;
        
        happy += X / 500 * 1000;
        X = X % 500;
        happy += X / 5 * 5;
        
        System.out.println(happy);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        
        int happy = 0;
        
        happy += X / 500 * 1000;
        X = X % 500;
        happy += X / 5 * 5;
        
        System.out.println(happy);
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        
        int happy = 0;
        
        happy += X / 500 * 1000;
        X = X % 500;
        happy += X / 5 * 5;
        
        System.out.println(happy);
    } main {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        
        int happy = 0;
        
        happy += X / 500 * 1000;
        X = X % 500;
        happy += X / 5 * 5;
        
        System.out.println(happy);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int X = sc.nextInt(); X sc.nextInt() sc.nextInt sc int happy = 0; happy 0 happy += X / 500 * 1000 happy X / 500 * 1000 X / 500 X 500 1000 X = X % 500 X X % 500 X 500 happy += X / 5 * 5 happy X / 5 * 5 X / 5 X 5 5 System.out.println(happy) System.out.println System.out System System.out happy String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        
        int happy = 0;
        
        happy += X / 500 * 1000;
        X = X % 500;
        happy += X / 5 * 5;
        
        System.out.println(happy);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        
        int happy = 0;
        
        happy += X / 500 * 1000;
        X = X % 500;
        happy += X / 5 * 5;
        
        System.out.println(happy);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        
        int happy = 0;
        
        happy += X / 500 * 1000;
        X = X % 500;
        happy += X / 5 * 5;
        
        System.out.println(happy);
    }
}
