import sys
sys.setrecursionlimit(100000000)
MOD = 10 ** 9 + 7
INF = 10 ** 15
dy = (-1,0,1,0)
dx = (0,1,0,-1)


def main():
    N = int(input())
    ans = 0
    for bit in range(1<<6):
        kind = 0
        for i in range(6):
            if (bit>>i)&1:
                kind += 1
        ret = pow(kind/6,N)
        if kind&1:
            ans -= ret
        else:
            ans += ret
    print("{:.7f}".format(abs(ans)))
if __name__ == '__main__':
    main()