#include <bits/stdc++.h>
using namespace std;
int n, ar[1000008];
int main() {
  cin >> n;
  ar[1] = 1;
  ar[2] = 3;
  for (int i = 3; i <= n; i++) {
    ar[i] = (ar[i - 1] + 1 + ar[i - 2] + 1) % 1000000007;
  }
  cout << ar[n] << endl;
  return 0;
}
