#include <bits/stdc++.h>
using namespace std;
int make(int x) {
  if (x % 2)
    return (x * x) / 2 + 1;
  else
    return (x * x / 2);
}
int main() {
  int x;
  cin >> x;
  if (x == 3) {
    cout << 5 << endl;
    return 0;
  }
  for (int i = 1;; i++) {
    int cur;
    if (i % 2)
      cur = (i * i) / 2 + 1;
    else
      cur = make(i / 2 - 1) * 4;
    if (cur >= x) {
      cout << i << endl;
      return 0;
    }
  }
  return 0;
}
