import java.util.*;
public class Main
{
    public static void main(String []args)
    {
        Scanner sc=new Scanner(System.in);
        int a=sc.nextInt();
            for(int i=0;i<1000;i++)
            {
                if((a+i)%1000==0)
                { 
                    System.out.println(i);
                    System.exit(0);
                }
            }
    }
}

/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