#include<string>
#include<deque>
#include<queue>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<cmath>
#include<tuple>
#include<map>
#include<functional>
using namespace std;
typedef long long int llint;
typedef bool izryt;
#define mp make_pair
#define mt make_tuple
#define pub push_back
#define puf push_front
#define pob pop_back
#define pof pop_front
#define fir first
#define sec second
#define res resize
#define ins insert
#define era erase
const int big=1e9;
const int mod=1e9 + 7;
int main(void){
	int i,j,n,m;cin>>n;
	vector<llint>dp[3];
	dp[0].res(n+10);
	dp[1].res(n+10);
	dp[2].res(n+10);
	dp[0][1]=1;
	dp[1][2]=1;
	dp[2][3]=1;
	for(i=0;i<n;i++){
		dp[0][i+1]+=dp[1][i]+dp[2][i];
		dp[1][i+2]+=dp[0][i]+dp[2][i];
		dp[2][i+3]+=dp[0][i]+dp[1][i];
		dp[0][i+1]%=mod;
		dp[1][i+2]%=mod;
		dp[2][i+3]%=mod;
	}
	cout<<(dp[0][n]+dp[1][n]+dp[2][n])%mod<<endl;
	return 0;
}