Divisibility Problem

solution.java

import java.util.*;
 
public class cf {
 
    public static void main(String[] args) {
        // Use the Scanner class
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.nextLine());
         for (int i = 0; i < n; i++) {
             String s   = sc.nextLine();
             String[] result = s.split(" ");
             int a = Integer.parseInt(result[0]);
             int b = Integer.parseInt(result[1]);
             if (b > a) {
                 System.out.println(b-a);
             } else if (a % b == 0){
                 System.out.println(0);
             } else {
                 System.out.println(((a/b)*b + b)-a);
             }
         }
    }
}