#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 <string.h>
#include <utility>

typedef long long ll;
using namespace std;

typedef pair<int, int> P;


int main() {
	unsigned long long m = 1e9 + 7;

	int n=0;
	cin>>n;

	vector<ll> ans;

	ans.push_back(1);
	ans.push_back(2);
	ans.push_back(2);

	for(int i=3; i<n; i++){
		ans.push_back((ans[i-2]+ans[i-3])%m);
	}

	cout<<ans[n-1]<<endl;
	return 0;
}