When a user answers the question are they taking a class, no matter what they enter to goes straight to asking what's their grade. How am I using the if else statement wrong?

#include <iostream>
using namespace std;

int main()
{
  char classYN, grade;

  cout << "Are you taking a class? (Enter Y,y, N, or n) " << endl;
  cin >> classYN;

  if (classYN  == 'y' || 'Y')
    {
      cout << "Please enter a letter grade: " << endl;
      cin >> grade;
    }
  else if (classYN  == 'n' || 'N')
      {
      cout << "Thanks for using the system." << endl;
      }
  else
    {
      cout << "Invalid input" << endl;
    }

  switch (grade)
    {
    case A || B:
      cout << "Great job!" << endl;
      break;
return 0;

 }