mod = 10**9+7
N = int(input())
DP = [[0] * 3 for _ in range(N+1)]
DP[0][0] = 1
for i in range(N):
    for j in range(3):
        if j <= 1:
            DP[i+1][j+1] += DP[i][j]
            DP[i+1][j+1] %= mod
        if 1 <= j:
            DP[i+1][0] += DP[i][j]
            DP[i+1][0] %= mod
print(sum(DP[N])%mod)