#include <bits/stdc++.h>

using namespace std;

const int MOD = 1000000007;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int N;
  cin >> N;
  vector dp(N + 5, vector(3, 0));
  dp[0][0] = 1;
  for (int i = 0; i < N; i++) {
    dp[i + 1][0] += (dp[i + 1][0] + (dp[i][1] + dp[i][2]) % MOD) % MOD;
    dp[i + 1][1] += dp[i][0];
    dp[i + 1][2] += dp[i][1];
    dp[i + 1][0] %= MOD;
    dp[i + 1][1] %= MOD;
    dp[i + 1][2] %= MOD;
  }
  cout << (dp[N][0] + dp[N][1] + dp[N][2]) % MOD << '\n';
  return 0;
}