#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int num = 0;
  if (n == 3) {
    cout << 5;
    return 0;
  }
  for (int i = 1; i < 100; i += 2) {
    if (ceil((i * i) / 2.0) >= n) {
      cout << i << "\n";
      break;
    }
  }
}
