import numpy as np

N=int(input())
def mat(A, N):
    if N == 0:
        return np.eye(6)
    elif N == 1:
        return A
    else:
        if N % 2 == 0:
            X = mat(A, N//2)
            return np.dot(X, X)
        else:
            X = mat(A, N//2)
            return np.dot(A, np.dot(X, X))


A = np.zeros((6, 6),dtype="float")
for i in range(5):
    A[i][i] += i+1
    A[i][i+1] += 5-i
A[5][5]=6
A /= 6
X0 = np.array([1, 0, 0, 0, 0, 0])
X0 = np.dot(X0, mat(A, N-1))

print(X0[-1])