#include <bits/stdc++.h>
using namespace std;
struct Edge {
  int src, dst;
  int weight;
  Edge(int src, int dst, int weight) : src(src), dst(dst), weight(weight) {}
};
bool operator<(const Edge &e, const Edge &f) {
  return e.weight != f.weight ? e.weight > f.weight
         : e.src != f.src     ? e.src < f.src
                              : e.dst < f.dst;
}
const int MAXN = 100;
int main() {
  int x, n;
  cin >> x;
  for (n = 1; n * n / 2 + 1 < x; n += 2)
    ;
  cout << (x == 3 ? 5 : n) << endl;
  return 0;
}
