#include <bits/stdc++.h>
int x;
int solve() {
  if (x == 1) return 1;
  if (x == 2) return 3;
  if (x == 3) return 5;
  int i = 1;
  while (i * i / 2 + 1 < x) i += 2;
  return i;
}
int main() {
  scanf("%d", &x);
  printf("%d\n", solve());
}
