import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        for (int i = 0; i < n; i++) {

            int stone = sc.nextInt();
            int player = sc.nextInt();

            int winner = stone % player;

            if (winner == 0) {
                winner = player;
            }

            System.out.println(winner);

        }

    }

}

Create : 0297