mod = 1000000007
eps = 10**-9


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

    def guchoku(N, M):
        res = float("inf")
        for P in permutations(list(range(1, N+1))):
            A = list(range(1, N+1))
            ans = 0
            for p in P[:-1]:
                tmp = M
                for a in A:
                    if a == p:
                        continue
                    tmp = min(tmp, (a + p) % M)
                ans += tmp
                A.remove(p)
            res = min(res, ans)
        return res

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

        #print(guchoku(N, M))


if __name__ == '__main__':
    main()