#include <bits/stdc++.h>
using namespace std;
long long sharp;
void solve() {
  if (sharp == 3) {
    cout << 5;
    return;
  }
  long long i = 1;
  while (i * i / 2 + 1LL < sharp) i += 2;
  cout << i << "\n";
}
void input() { cin >> sharp; }
void test_case() {
  input();
  solve();
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int q, multicase = 0;
  if (multicase)
    cin >> q;
  else
    q = 1;
  for (int i = 1; i <= q; ++i) test_case();
}
