#include<iostream>
#include<algorithm>
using namespace std;
using lint=int64_t;

const int mod=1e9+7;

int main()
{
	int N;

	cin >> N;

	int dp[1000010][3]={};
	dp[0][0]=1;
	for(int i=0;i<N;i++)
	{
		dp[i+1][0]+=(dp[i][1]+dp[i][2]);
		dp[i+1][1]+=dp[i][0];
		dp[i+1][2]+=dp[i][1];
		dp[i+1][0]%=mod;
		dp[i+1][1]%=mod;
		dp[i+1][2]%=mod;
	}

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