#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<utility>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<functional>
#include<math.h>
using namespace std;
#define N (1000000000+7)
//#define N (998244353)
#define INF 1e16
typedef long long ll;
typedef pair<ll,ll> P;
typedef vector<ll> vec;
typedef vector<vec> mat;

const int inf = 1e9;

ll dp[1000010][4];


int main(void){
    ll n;
    cin>>n;
    dp[1][1]=1;
    dp[2][2]=1;
    dp[3][1]=1;
    dp[3][2]=1;
    dp[3][3]=1;
    for(int i=4;i<=n;i++){
        for(int j=1;j<=3;j++){
            if(j==1){
                dp[i][1] = (dp[i-1][2]+dp[i-1][3])%N;
            }
            if(j==2){
                dp[i][2] = (dp[i-2][1]+dp[i-2][3])%N;
            }
            if(j==3){
                dp[i][3] = (dp[i-3][1]+dp[i-3][2])%N;
            }
        }
    }
    cout<<((dp[n][1]+dp[n][2])%N+dp[n][3])%N<<endl;
}