#include <bits/stdc++.h>
using namespace std;
const long double pi = 3.1415926535897932384626433;
const int mod = 1e9 + 7;
const long long inf = 3e18;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long n;
  cin >> n;
  vector<long long> dp(n + 1, 0);
  dp[1] = 1;
  dp[2] = 2;
  long long s = 3;
  for (long long i = 3; i <= n; i++) {
    dp[i] = ((dp[i - 1] % mod) + (dp[i - 2] % mod)) % mod;
    s = (s % mod + dp[i] % mod) % mod;
  }
  if (n == 1)
    cout << 1;
  else
    cout << s;
}
