mod = 10 ** 9 + 7

n = int(input())
dp = [[0] * 3 for _ in range(n + 5)]
dp[1][0] = 1
dp[2][1] = 1
dp[3][2] = 1

for i in range(1, n + 1):
    for j in range(3):
        for k in range(3):
            if j == k:
                continue
            dp[i+k+1][k] += dp[i][j]
            dp[i+k+1][k] %= mod

ans = sum(dp[n][i] for i in range(3))
print(ans % mod)