#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
#include<cmath>
using namespace std;

#define REP(i,n) for(int i=0;(i)<(n);(i)++)
#define ll long long

static const ll MOD = 1000000007;
ll dp[3][1000006];//ケンケン，ケンパ，パケンの3パターン×N

int main() {
	ll N;
	cin >> N;
	

	dp[0][1] = 0; dp[1][1] = 0; dp[2][1] = 1;
	for (int i = 2;i <= N;i++) {
		dp[0][i] = dp[2][i - 1] % MOD;
		dp[1][i] = ( dp[0][i - 1] + dp[2][i - 1] ) % MOD;
		dp[2][i] = dp[1][i - 1] % MOD;
	}

	ll ans = ( dp[0][N] + dp[1][N] + dp[2][N] ) % MOD;

	cout << ans << endl;
	//return 0;
}