#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int s0 = 0, s1 = 0;
  const int BASE = 1e+9 + 7;
  for (int i = 0; i < n; i++) {
    swap(s0, s1);
    s0 = (s0 + s1 + 1) % BASE;
  }
  cout << (s0 + s1) % BASE;
}
