#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9 + 9;
int f(int n) { return (n * n + 1) / 2; }
int main(int argc, char *argv[]) {
  int x;
  cin >> x;
  if (x == 3) x = 6;
  int n = 1;
  while (f(n) < x) {
    n += 2;
  }
  cout << n << '\n';
  return 0;
}
