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