//Yukicoder
//Q314 ken-pa


//二次元可変配列
//vector <vector <int>> mass;
//vector <vector <int>> memo;

//#include "stdafx.h"
#include <iostream>
#include <vector>
#include <list>//list
#include <set> //tree
#include <map> //連想配列
#include <unordered_set> //hash
#include <unordered_map> //hash
#include <algorithm>
#include <iomanip>

using namespace std;
typedef unsigned long long LL;


#define START (0)
#define RIGHT (1)
#define UP    (2)
#define LEFT  (3)
#define DOWN  (4)

#define DATA_MAX (1000000)
#define FMAX(a,b)  ((a)>(b)?(a):(b))
#define FMIX(a,b)  ((a)<(b)?(a):(b))


vector <vector <LL>> memo2;
vector<LL> memo1;
vector<LL> T;
vector<LL> K;
vector<LL> dp;

LL N, D;
LL ans = 0;





int main()
{
	LL total = 0;

	cin >> N;


	dp.resize(N + 10);



	if (N == 1)
	{
		cout << 1 << endl;
		return 0;
	}
	else
	if (N == 2)
	{
		cout << 2 << endl;
		return 0;
	}
	else
	if (N == 3)
	{
		cout << 2 << endl;
		return 0;
	}


	// 初期値
	dp[0] = 1; dp[1] = 2; dp[2] = 2;

	LL n = 3;

	while (1)
	{
		
		dp[n] = (dp[n - 2] + dp[n - 3]) % 1000000007; //毎回 mod を取る
		n++;
		if (n >= N)
			break;
	}


	cout << dp[n-1]  << endl;

	//getchar();
	return 0; //end
}