#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define MOD 1000000007

typedef long long ll;

int main()
{
	int N; cin >> N;
	ll ken = 1, kenken = 0, pa = 0;
	rep(i, 1, N)
	{
		ll _ken = ken, _kenken = kenken, _pa = pa;
		ken = _pa;
		kenken = _ken;
		pa = (_ken + _kenken) % MOD;
	}
	cout << (ken + kenken + pa) % MOD << endl;
}