#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int x, i, curr = 3, b;
  cin >> x;
  long long int a[100];
  for (i = 0; i < 100; i++) a[i] = 0;
  a[0] = 1;
  a[1] = 3;
  a[2] = 5;
  for (i = 3; i < 100; i++) {
    b = ((curr * curr) + 1) / 2;
    if (i + 1 < b)
      a[i] = curr;
    else if (i + 1 == b) {
      a[i] = curr;
      curr = curr + 2;
    }
  }
  cout << a[x - 1] << endl;
}
