import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        int result = 0;
        if(x % 500 == 0) {
        	result = 1000 * (x / 500);
        }else {
        	result = 1000 * (x / 500) + (x % 500) / 5 * 5;
        }
        System.out.print(result);
        
	}
}
/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