#include <bits/stdc++.h>
using namespace std;
int n;
static int a[5] = {1, 3, 5, 3, 3};
static int b[7] = {3, 5, 7, 9, 11, 13, 15};
static int c[7] = {5, 13, 25, 41, 61, 85, 113};
int main() {
  scanf("%d", &n);
  if (n <= 5)
    printf("%d\n", a[n - 1]);
  else
    printf("%d\n", b[upper_bound(c, c + 7, n - 1) - c]);
  return 0;
}
