n = int(input())
mod = 10**9 + 7

DP = [[0 for _ in range(4)] for _ in range(n + 1)]
DP[0][1] = 1
for i in range(n):
    for j in range(1, 4):
        for k in range(1, 4):
            if j == k:
                if i == 0:
                    if i + k <= n:
                        DP[i + k][k] += DP[i][j]
                        DP[i + k][k] %= mod
            else:
                if i + k <= n:
                    DP[i + k][k] += DP[i][j]
                    DP[i + k][k] %= mod
ans = 0
for i in range(1, 4):
    ans += DP[n][i]
    ans %= mod
print(ans)