#include <bits/stdc++.h>
using namespace std;
int main() {
  int r, x, s = 1;
  scanf("%d", &x);
  for (r = 1;; r += 2)
    if (((r * r + 1) >> 1) >= x) break;
  printf("%d\n", (x == 3) ? 5 : r);
  return 0;
}
