def f(n):
    for i in range(2, 16384):
        x = i ** n
        if x > 1000000000:
            break
        t.append(1 / x)


x = int(input())

t = []
for i in range(x, 128):
    f(i)

while len(t) != 1:
    nt = []
    for i in range(0, len(t), 2):
        nt.append(t[i] + t[i + 1])
    t = nt

print(int(t[0] * (10 ** 6)))