#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, r = 0;
  long long f[1000001];
  f[0] = 1;
  f[1] = 1;
  for (int i = 2; i < 1000001; i++) {
    f[i] = f[i - 2] + f[i - 1];
    f[i] %= 1000000007;
  }
  cin >> a;
  for (int i = 1; i <= a; i++) {
    r += f[i];
    r %= 1000000007;
  }
  cout << r << endl;
}
