#include <bits/stdc++.h>
using namespace std;
int solve() {
  int x;
  cin >> x;
  if (x == 1) return 1;
  if (x == 2) return 3;
  if (x == 3) return 5;
  for (int k = 1; k < x; k++) {
    if ((k * k + (k - 1) * (k - 1) < x) && (x <= k * k + (k + 1) * (k + 1)))
      return 2 * k + 1;
  }
  return 0;
}
int main() { cout << solve() << endl; }
