#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  long long a[n + 5];
  a[0] = 0;
  a[1] = 1;
  for (long long i = 2; i <= n + 5; i++)
    a[i] = (a[i - 1] + a[i - 2] + 2) % 1000000007;
  return cout << a[n] << endl, 0;
}
