import sys
input = sys.stdin.readline

def main():
    n = int(input())

    m = 2**6
    num = [2**i for i in range(6)]

    dp = [[0 for i in range(m)] for j in range(n+1)]
    dp[0][0] = 1

    for i in range(1, n+1):
        for j in range(m):
            for k in range(6):
                dp[i][j | num[k]] += dp[i-1][j] / 6

    print(dp[-1][-1])

if __name__ == '__main__':
    main()