#include <bits/stdc++.h>
const int maxn = 1000007;
const long long mod = 1e9 + 7;
int main() {
  int n;
  std::cin >> n;
  long long now = 1, last = 1;
  for (int i = 1; i <= n; i++) {
    now += last;
    now %= mod;
    last %= mod;
    std::swap(now, last);
  }
  std::cout << (now + last - 2 + mod) % mod << "\n";
}
