mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    for _ in range(int(input())):
        N, M = map(int, input().split())
        if M == 1:
            print(0)
            continue
        if M <= N:
            print((M - 1) // 2 + 1)
        elif M == 2 * N:
            print(N - 1 + (N * (N + 1)) // 2 - 1)
        else:
            K = M - N - 1
            if K == 0:
                print((N - 1) // 2)
            else:
                print((N - K - 1) // 2 + K + ((K + 1) * (K + 2)) // 2 - 1)


if __name__ == '__main__':
    main()