#include<iostream>
using namespace std;

long long mod = 1e9 + 7, dp[1000000][4];

int main()
{
	int n;

	cin >> n;

	dp[1][1] = 1;
	dp[1][2] = 0;
	dp[1][3] = 0;
	dp[2][1] = 0;
	dp[2][2] = 1;
	dp[2][3] = 0;
	dp[3][1] = 1;
	dp[3][2] = 1;
	dp[3][3] = 1;

	for (int i = 4; i <= n; i++)
	{
		dp[i][1] = (dp[i - 1][2] + dp[i - 1][3]) % mod;
		dp[i][2] = (dp[i - 2][1] + dp[i - 2][3]) % mod;
		dp[i][3] = (dp[i - 3][1] + dp[i - 3][2]) % mod;
	}

	cout << (dp[n][1] + dp[n][2] + dp[n][3]) % mod << endl;
}