#include <bits/stdc++.h>
using namespace std;
long long sum[1000001];
int main() {
  long long n, tong = 3, mod = 1e9 + 7;
  cin >> n;
  sum[1] = 1, sum[2] = 2;
  for (long long i = 3; i <= n; i++) {
    sum[i] = (sum[i - 1] + sum[i - 2]) % mod;
    tong = (tong + sum[i]) % mod;
  }
  if (n == 1)
    cout << 1;
  else
    cout << tong;
}
