def test(x):
    sq = 12 * x + 1
    ss = int(sq ** 0.5)
    if ss * ss != sq:
        return False
    if ss % 6 != 5:
        return False
    return True

def main(limit):
    for d in range(1, limit):
        for n in range(5, limit):
            m = n + d
            a = 3 * (m * m + n * n) - m - n
            b = d * (3 * (m + n) - 1)
            if test(a) and test(b):
                return b // 2

print(main(1300))