import java.io.*; 
  
public class PassingGradeIB 
{ 
  public static void main(String[] argv) throws Exception 
  { 
    BufferedReader cin; 
    cin = new BufferedReader(new InputStreamReader(System.in)); 
  
    while (true) 
    { 
      char grade; 
      System.out.print("What is your grade? [A, B, C, D, F, or X to quit]: "); 
      grade = cin.readLine().charAt(0); 
  
      if (grade == 'X' || grade == 'x') break; 
  
      if (grade == 'A' || grade == 'B' || grade == 'C') 
        System.out.println("You pass"); 
    } // while 

    System.out.println("Thanks for checking your grades!"); 
  } // main 
} // public class