#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, n;
  int a[100];
  for (int i = 1; i < 100; i += 2) {
    a[i] = (i * i + 1) / 2;
  }
  scanf("%d", &n);
  for (int i = 1; i < 100; i += 2) {
    if (a[i] >= n) {
      x = i;
      break;
    }
  }
  printf("%d\n", n == 3 ? 5 : x);
  return 0;
}
