#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int n;
  cin >> n;
  if (n == 1)
    cout << "1";
  else if (n <= 5 && n != 3)
    cout << "3";
  else if (n <= 13)
    cout << "5";
  else if (n <= 25)
    cout << "7";
  else if (n <= 41)
    cout << "9";
  else if (n <= 61)
    cout << "11";
  else if (n <= 85)
    cout << "13";
  else
    cout << "15";
  return 0;
}
