#include <bits/stdc++.h>
using namespace std;
long long oo = (long long)(1e10);
long long dp[(long long)(1e6 + 15)];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr), cout.tie(nullptr);
  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]) % (long long)(1000000000 + 7);
    dp[i] = (dp[i] + 2) % (long long)(1000000000 + 7);
  }
  cout << dp[n];
  return 0;
}
