Problem:
Score : 100 points

Problem Statement

We will buy a product for N yen (the currency of Japan) at a shop.

If we use only 1000-yen bills to pay the price, how much change will we receive?

Assume we use the minimum number of bills required.

Constraints

1 \leq N \leq 10000

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the amount of change as an integer.

Sample Input 1

1900

Sample Output 1

100

We will use two 1000-yen bills to pay the price and receive 100 yen in change.

Sample Input 2

3000

Sample Output 2

0

We can pay the exact price.

Solution in C (Clang 10.0.0) (judge verdict: Wrong Answer)

#include <stdio.h>

int main()
{

printf("購入した商品の値段を入力してください\n");
int N;
scanf("%d",&N);
 for (int i = 1; i < 11; i++){
 int u = i*1000;
 if(N <= u){
 int x;
 x = u - N;
// if(N == u){
  printf("%d\n",x);break;
  // printf("円ちょうどですね。ありがとうございました。");break;
// }
 //printf("
 //1000円札%d枚でお支払ですね。お釣りは%d円になりますn", i,x);break;
 }
}
}