while True:

    (n, x) = [int(i) for i in input().split()]

    if n == x == 0:

        break



    count = 0

    for a in range(1, n + 1 - 2):

        for b in range(a + 1, n + 1 - 1):

            for c in range(b + 1, n + 1):

                if (a + b + c) == x:

                    count += 1

    print(count)
while True:

    (n, x) = [int(i) for i in input().split()]

    if n == x == 0:

        break

    count = 0

    for a in range(n if n < x else x, 2, -1):

        for b in range(a-1, 1, -1):

            if a + b > x:

                continue

            for c in range(b-1, 0, -1):

                s = a + b + c

                if s == x:

                    count += 1

                    break

                elif s < x:

                    break

    print(count)
while True:
    (n, x) = [int(i) for i in input().split()]
    if n == x == 0:
        break
    count = 0
    for a in range(1, n + 1 - 2):
        for b in range(a + 1, n + 1 - 1):
            for c in range(b + 1, n + 1):
                if (a + b + c) == x:
                    count += 1
    print(count)

while True:
    (n, x) = [int(i) for i in input().split()]
    if n == x == 0:
        break
    count = 0
    for a in range(n if n < x else x, 2, -1):
        for b in range(a - 1, 1, -1):
            if a + b > x:
                continue
            for c in range(b - 1, 0, -1):
                s = a + b + c
                if s == x:
                    count += 1
                    break
                elif s < x:
                    break
    print(count)

-    for a in range(1, n + 1 - 2): -        for b in range(a + 1, n + 1 - 1): -            for c in range(b + 1, n + 1): -                if (a + b + c) == x: +    for a in range(n if n < x else x, 2, -1): +        for b in range(a - 1, 1, -1): +            if a + b > x: +                continue +            for c in range(b - 1, 0, -1): +                s = a + b + c +                if s == x: +                    break +                elif s < x: +                    break