#include <bits/stdc++.h>
using namespace std;
int i, j, n, k, tot, ans, sum;
int a[100005];
string st;
char ch;
int main() {
  ios::sync_with_stdio(false);
  cin >> n;
  if (n == 2) {
    cout << 3 << endl;
    return 0;
  }
  if (n == 3) {
    cout << 5 << endl;
    return 0;
  }
  for (i = 1; i <= 100; i++) {
    if (i % 2 == 0) continue;
    j = (i * i + 1) / 2;
    if (j >= n) break;
  }
  cout << i << endl;
}
