#include <bits/stdc++.h>
using namespace std;
using namespace std::chrono;
long double PI = 3.14159265358979323846;
const int modo = 1e9 + 7;
const long long inf = 1e13;
const long long ms = (1e6) + 5;
int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr);
  int n;
  cin >> n;
  int i = 1;
  int a;
  int b;
  int aa;
  int bb;
  int tt;
  if (n == 3) {
    cout << "5";
    return 0;
  }
  while (true) {
    a = i / 2;
    b = (i + 1) / 2;
    tt = (a * a) + (b * b);
    if (n <= tt) {
      cout << i;
      break;
    }
    i += 2;
  }
  return 0;
}
