#include <bits/stdc++.h>
using namespace std;

int main() {
  int N;
  cin >> N;
  string Es = "1";
  for (int i = 0; i < N; i++) {
    Es += "3";
  }
  int E = stoi(Es);
  int A = E % 1000000007;
  cout << A << endl;
}