from functools import cache
import sys
sys.setrecursionlimit(10 ** 6)


@cache
def f(n: int):
    if n <= 0: return 0
    res = 1
    for i in range(1, 7):
        res += f(n - i) / 6
    return res


K = int(input())
ans = f(K)
print(ans)