#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <map>
#include <set>
#include <cstdio>
#include <cmath>
#define rep(i,l,n) for(int i=l;i<n;i++)
#define rer(i,l,n) for(int i=l;i<=n;i++)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
#define pb(a) push_back(a)
#define mk(a,b) make_pair(a,b)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pii;

lint a[1000001]={};
lint mod=1e9+7;

int main(){
	int n;
	a[1]=0; a[2]=1; a[3]=1;
	cin>>n;
	rep(i,4,n){
		a[i]=(a[i-2]+a[i-3])%mod;
	}
	if(n==1) o(1);
	else if(n==2||n==3) o(2);
	else{
		lint ans=(a[n-1]+2*a[n-2]+a[n-3])%mod;
		o(ans);
	}
}