#include <cstdio>
#include <cstring>
#include <string>
#include <iostream>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>
#include <random>
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;
const ll MOD=1e9+7;
int main()
{
	int n;
	cin>>n;
	ll dp[1000001][4]={};
	dp[0][0]=1;
	for(int i=1; i<=n; i++){
		for(int j=1; j<=3; j++){
			if(i<j) continue;
			for(int k=0; k<=3; k++){
				if(j==k) continue;
				dp[i][j]+=dp[i-j][k];
			}
			dp[i][j]%=MOD;
		}
	}
	cout<<(dp[n][1]+dp[n][2]+dp[n][3])%MOD<<endl;
	return 0;
}