N = int(input())
mod = 10 ** 9 + 7
pre = [0, 1, 0]
for i in range(N - 1):
    dp = [0] * 3
    dp[0] += pre[1] + pre[2]
    dp[0] % mod
    dp[1] += pre[0]
    dp[1] %= mod
    dp[2] += pre[1]
    dp[2] %= mod
    
    dp, pre = pre, dp
print(sum(pre)%mod)