from sys import stdin, stdout, stderr

def solve():
    mod = 10**9 + 7

    N = int(input())

    dp =[[0]*3 for i in range(2)]
    dp[0][0] = 1

    for i in range(1, N + 1):
        dp[i % 2][0] = (dp[(i - 1) % 2][1] + dp[(i - 1) % 2][2]) % mod
        dp[i % 2][1] = dp[(i - 1) % 2][0]
        dp[i % 2][2] = dp[(i - 1) % 2][1]
        # print(dp[i % 2])

    ans = sum(dp[N % 2])
    ans %= mod
    print(ans)

if __name__ == '__main__':
    solve()