n = int(input())


def nCk(n, k):
    ret = 1.0
    for i in range(1, n + 1):
        ret *= i
    for i in range(1, k + 1):
        ret /= i
    return ret


if n < 5:
    print(0)
else:
    ans = nCk(94, n - 5) / nCk(99, n)
    print(ans * 12)