#include <bits/stdc++.h>
using namespace std;
long long int i = 1, n, m, k, l, r, pi, pj, pk, ma, mi, a[1000001];
string s;
char q;
int main() {
  cin >> n;
  if (n == 3)
    cout << 5;
  else {
    for (; i * i / 2 + 1 < n; i += 2) i = i;
    cout << i;
  }
}
