#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  long long int prev = 1, next = 1, current;
  for (int i = 0; i <= n; i++) {
    current = (prev + next) % 1000000007;
    prev = next;
    next = current;
  }
  cout << (current - 2) % 1000000007 << endl;
}
