#include <iostream>
#include <utility>
#include <vector>
#include <string>
#include <cmath>
#include <algorithm>
#include <functional>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
using namespace std;
using ll = long long int;
#define chmax(x,y)  x = (x > (y)) ? x : (x = (y));
#define chmin(x,y)  x = (x < (y)) ? x : (x = (y));


int main(int argc, char const *argv[])
{
  int N; cin >> N;
  constexpr int Mod = 1e9 + 7;
  vector<vector<ll>> dp(N+1,vector<ll>(3));
  dp[0][0] = 1;
  for(int i=0;i<N;++i)
  {
    (dp[i+1][2] += dp[i][0]%Mod) %= Mod;
    (dp[i+1][1] += dp[i][0]%Mod) %= Mod;

    (dp[i+1][2] += dp[i][1]%Mod) %= Mod;

    (dp[i+1][0] += dp[i][2]%Mod) %= Mod;
  }
  ll answer = dp[N-1][0]%Mod + dp[N-1][1]%Mod + dp[N-1][2]%Mod;
  answer %= Mod;
  std::cout << answer << std::endl;
}