import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int zankin = sc.nextInt();
        int i = 0;
        int j = 0;
      
      while (zankin - 500 * (i + 1) >= 0 ) {
        i = i + 1 ;
      }
      zankin = zankin - 500 * i ;
      
      while (zankin - 5 * (j + 1) >= 0 ) {
        j = j + 1 ;
      }
      
      System.out.println(i * 1000 + j * 5);

    }
}


/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz