#!/usr/bin/env python3
# from typing import *


def solve(a, b):
    return b + a * b


# generated by oj-template v4.8.0 (https://github.com/online-judge-tools/template-generator)
def main():
    a = int(input())
    for i in range(a):
        b, c = map(int, input().split())
        print(solve(b, c))


if __name__ == '__main__':
    main()