#include <bits/stdc++.h>
using namespace std;
int main() {
  int x;
  cin >> x;
  if (x == 3)
    cout << 5 << endl;
  else {
    vector<int> v(16);
    for (int i = 1; i < 16; i += 2) v[i] = (i * i) / 2 + 1;
    int j = 1;
    while (j < 16 and x > v[j]) j += 2;
    cout << j << endl;
  }
}
