#include <bits/stdc++.h>
using namespace std;
const long long N = 100005;
const long long inf = 1000000000 + 7;
long long m, l, r, k, u, pat, q, z, x, n, y, ans;
int main() {
  cin >> n;
  x = y = 0;
  for (int i = 1; i <= n; i++) {
    swap(x, y);
    x = (x + y + 1) % inf;
  }
  cout << (x + y) % inf << endl;
  return 0;
}
