#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  if (n == 3 || n == 1) {
    if (n == 3)
      cout << 5 << endl;
    else
      cout << 1 << endl;
    return 0;
  }
  if (n & 1) n--;
  int t = 4;
  while (true) {
    n -= t;
    if (n <= 0) break;
    t += 4;
  }
  cout << t / 2 + 1 << endl;
  return 0;
}
