#include <iostream>
#include<vector>
#include<cmath>
using namespace std;

const int INF=1e9+7;
int N;

int main(){
    
    cin>>N;
    vector<vector<int> > dp(N+1,vector<int>(4,0));
    dp[1][1]=1;
    for(int i=1;i<N;i++){
        (dp[i+1][1]+=dp[i][0])%=INF;
        (dp[i+1][0]+=dp[i][1]+dp[i][2])%=INF;
        (dp[i+1][2]+=dp[i][1])%=INF;
    }
    cout<<(dp[N][0]+dp[N][1]+dp[N][2])%INF<<endl;
}