#include <bits/stdc++.h>
const long long inf = 1e9;
const long long mod = 1e9 + 7;
const long long zero = 0;
const long long maxn = 1e5 + 5;
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n;
  cin >> 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 if (n <= 25) {
    cout << 7 << endl;
  } else if (n <= 41) {
    cout << 9 << endl;
  } else if (n <= 61) {
    cout << 11 << endl;
  } else if (n <= 85) {
    cout << 13 << endl;
  } else {
    cout << 15 << endl;
  }
}
