N = int(input())
DIV = 10 ** 9 + 7

dp = [0] * 4
dp[0] = 1

for _ in range(N):
    new_dp = [0] * 4
    for i in range(4):
        for j in range(4):
            if i == j:
                continue
            new_dp[j] += dp[i]
            new_dp[j] %= DIV
    dp = new_dp
    
print(dp[0])