#include <bits/stdc++.h>
using namespace std;
int i, x;
bool can(int N, int x) {
  if (N == 1) return (x <= 1);
  if (N == 2) return (x <= 0);
  if (N == 3) return (x <= 5 && x != 3);
  if (N % 2 == 1) return (x <= (N * N + 1) / 2);
  if (x % 4 != 0) return false;
  int n = N / 2 - 1;
  int ans = (n * n + 1) / 2;
  ans *= 4;
  return (x <= ans);
}
int main() {
  scanf("%d", &x);
  for (i = 1;; i++)
    if (can(i, x)) break;
  printf("%d\n", i);
  return 0;
}
