#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  long long m = 1e9 + 7, x, res = 1, a = 1, b = 1;
  cin >> x;
  for (long long i = 3; i <= x + 1; i++) {
    a %= m;
    b %= m;
    res %= m;
    res += (a + b) % m;
    int c = (a + b) % m;
    a = b;
    b = c;
  }
  cout << res % m;
}
