#include <iostream> 
using namespace std; 
  
int main() 
{ 
  while (true) 
  { 
    char grade; 
    cout << "What is your grade? [A, B, C, D, F, or X to quit]: "; 
    cin >> grade; 
    cin.ignore(1000, 10); 
  
    if (grade == 'X' || grade == 'x') break; 
  
    if (grade == 'A' || grade == 'B' || grade == 'C') 
      cout << "You pass" << endl; 
  } // while 
  
  cout << "Thanks for checking your grades!" << endl; 
} // main