import itertools
n = int(input())
l = 0
while (l**n < 10**6):
    l += 1
s = 0.0
for v in itertools.product(range(1, l), repeat=n):
    x = 0.0
    for i in v:
        x += i**-2
    p = v[0]**2
    for i in v:
        p *= i**2
    s += 1.0 / (p * x)
print(int(s))