def resolve():
    import sys

    input = lambda: sys.stdin.readline().rstrip()

    a, b = map(int, input().split())

    ans = - (((3 * a - 1) * b ** 3 - 3 * a * b ** 2 + (3 * a ** 2 - 3 * a ** 3) * b + a ** 3) / 3)
    print(abs(ans))


resolve()