#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 9;
int dp[N];
int main() {
  int n;
  cin >> n;
  dp[1] = 1;
  dp[2] = 3;
  for (int i = 3; i <= N; i++) {
    dp[i] = (dp[i - 1] + dp[i - 2] + 2) % 1000000007;
  }
  cout << dp[n] << endl;
}
