#include<iostream>
using namespace std;

long long mod = 1e9 + 7, dp[1000010][3];

int main()
{
	int n, i;

	cin >> n;

	dp[1][1] = 1;

	for (i = 2; i <= n; i++)
	{
		dp[i][0] = (dp[i - 1][1] + dp[i - 1][2]) % mod;
		dp[i][1] = dp[i - 1][0] % mod;
		dp[i][2] = dp[i - 1][1] % mod;
	}

	cout << (dp[n][0] + dp[n][1] + dp[n][2]) % mod << endl;
}