#include <bits/stdc++.h>
using namespace std;
int x, ans;
int main() {
  ios ::sync_with_stdio(0);
  cin >> x;
  if (x == 1)
    cout << 1 << endl;
  else if (x == 3)
    cout << 5 << endl;
  else {
    ans = 1;
    for (; (ans * ans / 2 + 1) < x; ans += 2)
      ;
    cout << ans << endl;
  }
}
