#include <bits/stdc++.h>
int Num[20] = {
    0, 1, 0, 5, 0, 13, 0, 25, 0, 41, 0, 61, 0, 85, 0, 113, 200,
};
int main() {
  int n, i;
  scanf("%d", &n);
  if (n == 3) {
    puts("5");
    return 0;
  }
  for (i = 1; i < 20; i++) {
    if (n <= Num[i]) break;
  }
  printf("%d\n", i);
  return 0;
}
