#include <bits/stdc++.h>
using namespace std;
int n, m, k;
string src[20];
string cur[20];
int main() {
  int x;
  cin >> x;
  if (x == 1) cout << 1;
  if (x == 2) cout << 3;
  if (x == 3)
    cout << 5;
  else if (x != 1 && x != 2 && x != 3) {
    n = 3;
    while ((n * n) / 2 + 1 < x) n += 2;
    cout << n;
  }
  return 0;
}
