//#include <bits/stdc++.h>
#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <iomanip>
#include <math.h> 
#include <stack>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <tuple>
#include <cctype>
#include <ctype.h>
#include <set>
#include <sstream>
#include <time.h>
using namespace std;
#define int long long
#define rep(i,s,n) for(int i = s;i<n;i++)
#define repe(i,s,n) for(int i = s;i<=n;i++)
#define rrep(i,s,n) for(int i = (n)-1;i>=(s);i--)
#define all(v) (v).begin(),(v).end()
#define pb push_back
#define fi first
#define se second
#define chmin(a,b) a=min((a),(b))
#define chmax(a,b) a=max((a),(b))
typedef long long ll;
typedef pair<int, int>pint;
typedef vector<int>vint;
typedef vector<pint>vpint;
typedef pair<pint, int> P1;
typedef pair<int, pint> P2;
typedef pair<pint, pint> PP;
static const ll maxLL = (ll)1 << 62;
const ll MOD = 1000000007;
const ll INF = 1e18;
int ca[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };



signed main() {
	int i, j, n, cnt = 0;
	string s;
	vint list;
	double a;
	vector<vint>dp(1000006, vint(4, 0));

	
	cin >> n;


	dp[0][0] = 1;
	dp[1][1] = 1;
	dp[2][2] = 1;
	dp[3][3] = 1;

	

	rep(i, 0, n) {
		
		dp[i + 1][1] += ( dp[i][2] + dp[i][3] ) % MOD;
		dp[i + 2][2] += ( dp[i][1] + dp[i][3] ) % MOD;
		dp[i + 3][3] += ( dp[i][1] + dp[i][2] ) % MOD;
	

	}


	cout << (dp[n][1] + dp[n][2] + dp[n][3])%MOD << endl;





	getchar();
	getchar();
	return 0;
}