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: Accepted)

function main(lines) {
  const N = +lines[0];
  
  let res;
  
  for (let i = 1000; i <= 10000; i += 1000) {
    if (i >= N) {
      res = i - N;
      break;
    }
  }
  
  console.log(res);
}


main( require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n") );



function splitN(s) {
  return s.split(' ').map(Number);
}