MOD = 10 ** 9 + 7

n = int(input())
dp = [[0, 0, 0, 0] for _ in range(n + 1)]
dp[0][0] = 1
for i in range(1, n + 1):
    for j in range(4):
        for k in range(4):
            if j == k:
                continue
            dp[i][j] += dp[i - 1][k]
            dp[i][j] %= MOD
print(dp[-1][0])