import java.util.Scanner;
class Main{
public static void main(String[]args){

Scanner sc= new Scanner(System.in);
int X =sc.nextInt();

int tho = X/500;
int A =X-500*tho;
int five = A/5;
  
int ans=tho*1000+five*5;

System.out.println(ans);
}
}
/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