#pragma region include
#include <iostream>
#include <iomanip>
#include <stdio.h>

#include <sstream>
#include <algorithm>
#include <cmath>
#include <complex>

#include <string>
#include <cstring>
#include <vector>
#include <tuple>
#include <bitset>

#include <queue>
#include <complex>
#include <set>
#include <map>
#include <stack>
#include <list>

#include <fstream>
#include <random>
//#include <time.h>
#include <ctime>
#pragma endregion //#include
/////////
#define REP(i, x, n) for(int i = x; i < n; ++i)
#define rep(i,n) REP(i,0,n)
/////////
#pragma region typedef
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
#pragma endregion //typedef
////定数
const int INF = (int)1e9;
const LL MOD = (LL)1e9+7;
const LL LINF = (LL)1e18;
const double PI = acos(-1.0);
const double EPS = 1e-9;
/////////
using namespace::std;

void solve(){
	int N;
	cin >> N;
	vector< vector<LL> > dp(N+1+10,vector<LL>(4,0));
	//dp[i][pat],iステップ目で直前にpatで来た
	dp[1][1] = 1;
	dp[2][2] = 1;
	dp[3][3] = 1;
	for(int i=1;i<N;++i){
		for(int step=1;step<=3;++step){
			if( dp[i][step] == 0 ) continue;
			for(int j=1;j<=3;++j){
				if( j == step ) continue;//連続はだめ
				dp[i+j][j] += dp[i][step];
				if( dp[i+j][j] >= MOD ){
					dp[i+j][j] -= MOD;
				}
			}
		}
	}
	LL ans = 0;
	for(int step=1;step<=3;++step){
		ans += dp[N][step];
		if( ans >= MOD ){
			ans -= MOD;
		}
	}
	cout << ans << endl;
}
#pragma region main
signed main(void){
	std::cin.tie(0);
	std::ios::sync_with_stdio(false);
	std::cout << std::fixed;//小数を10進数表示
	cout << setprecision(16);//小数点以下の桁数を指定//coutとcerrで別	
	
	solve();
}
#pragma endregion //main()