#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, a = 1, b = 0;
  cin >> x;
  if (x == 3)
    cout << "5";
  else {
    int i = 1;
    while (true) {
      if (x <= a * a + b * b) {
        cout << i;
        break;
      }
      i += 2;
      a++;
      b++;
    }
  }
  return 0;
}
