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