#include<bits/stdc++.h>
using namespace std;
long long N;
long long mod=1000000007;
long long memo[1000009][5];

int main(){
  cin >> N;
  memo[1][1]=1;
  memo[2][2]=1;
  memo[3][3]=1;
  memo[3][1]=1;
  memo[3][2]=1;
  for(int i=4;i<=N;i++){
    memo[i][1]=(memo[i-1][2]+memo[i-1][3])%mod;
    memo[i][2]=(memo[i-2][1]+memo[i-2][3])%mod;
    memo[i][3]=(memo[i-3][1]+memo[i-3][2])%mod;
  }
  cout << (memo[N][1]+memo[N][2]+memo[N][3])%mod << endl;
}