#include<bits/stdc++.h>
using namespace std;
#ifdef LOCAL_DEBUG
  #include "LOCAL_DEBUG.hpp"
#endif
#define int long long
const int MOD = 1e9 + 7;

signed main(){

  int n; cin >> n;

  static int dp[1000011][3];
  dp[1][0] = 1, dp[2][1] = 1, dp[3][2] = 1; 
  for(int i = 0; i < n; i++){
    for(int j = 0; j < 3; j++){
      for(int k = 0; k < 3; k++){
        if(j == k) continue;
        dp[i+k+1][k] = (dp[i+k+1][k] + dp[i][j]) % MOD;
      }
    }
  }
  int ans = (dp[n][0] + dp[n][1] + dp[n][2]) % MOD;
  cout << ans << endl;

  return 0;
}