def f(n, m, k):
    if n < m + k and m < n + k and k < n + m:
        return True
    else:
        return False
def F(x, A):
    return not((f(x, 11, 18) == (not(max(x, 5) > 68))) and f(x, A, 5))
Max = 0
for A in range(1, 1000):
    if all(F(x, A) == 1 for x in range(0, 1000)):
        Max = max(A, Max)
print(Max)