#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  scanf("%d", &n);
  if (n == 1)
    cout << "1" << endl;
  else if (n == 3)
    cout << "5" << endl;
  else if (n <= 5)
    cout << "3" << endl;
  else if (n <= 13)
    cout << "5" << endl;
  else {
    int count = 7;
    int four = 3, ans = 13;
    while (1) {
      ans = ans + four * 4;
      if (n <= ans) {
        cout << count << endl;
        break;
      } else {
        four += 1;
        count += 2;
      }
    }
  }
  return 0;
}
