#include <bits/stdc++.h>
#include "bits/stdc++.h"
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cmath>
#include <stack>
#include <queue>
#include <cctype>
#include <stdio.h>
#include <map>
#include <unordered_map>
#include <string.h>
#include <utility>

typedef long long ll;

#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
using namespace std;

typedef pair<int, int> P;

ll kenkenpa[1000001][4];


int main() {

	int n;
	cin>>n;

	kenkenpa[1][1] =1;

	for(int i=2; i<=n; i++){

		kenkenpa[i][0] = (kenkenpa[i-1][1]+kenkenpa[i-1][2])%1000000007;

		kenkenpa[i][1] = kenkenpa[i-1][0]%1000000007;

		kenkenpa[i][2] = kenkenpa[i-1][1]%1000000007;
	}

	cout<<(kenkenpa[n][0]+kenkenpa[n][1]+kenkenpa[n][2])%1000000007<<endl;

}