#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  vector<int> dp(1000007, 0);
  dp[1] = 1;
  dp[2] = 3;
  cin >> n;
  if (n == 1)
    cout << 1 << endl;
  else {
    if (n == 2)
      cout << 3 << endl;
    else {
      for (int i = 3; i <= n; i++) {
        dp[i] = (dp[i - 1] + dp[i - 2] + 2) % 1000000007;
      }
      cout << dp[n] << endl;
    }
  }
}
