#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9 + 7;
const int N = 1e6 + 100;
int f[N];
signed main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  f[1] = f[2] = 1;
  for (int i = 3; i < N; i++) {
    f[i] = (f[i - 1] + f[i - 2]) % MOD;
  }
  int n;
  cin >> n;
  int ans = (f[n + 3] + MOD - 2) % MOD;
  cout << ans << '\n';
}
