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 JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

function Main(input) {
	input = input.split("\n");
	
	var n = parseInt(input[0], 10);
	
	var result = n
	for (var i = 1; i < 11; i++) {
	if  (result < 1000) {
	break;
	} else {
	result = result - 1000;
	}
	}
	
	result = 1000 - result
	
	console.log(result);
	}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));