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