#include <bits/stdc++.h>
using namespace std;
int main() {
  int x;
  cin >> x;
  int i;
  for (i = 1;; i += 2) {
    if ((i * i + 1) / 2 >= x) {
      break;
    }
  }
  if (x == 3)
    cout << "5\n";
  else
    cout << i << endl;
}
