public static void writeBackward(String s, int size) {
// ---------------------------------------------------
// Writes a character string backward.
// Precondition: The string s contains size 
// characters, where size >= 0.
// Postcondition: s is written backward, but remains
// unchanged.
// ---------------------------------------------------
  if (size > 0) {
    // write the last character
    System.out.println(s.substring(size-1, size));

    // write the rest of the string backward
    writeBackward(s, size-1);  // Point A
  }  // end if
  // size == 0 is the base case - do nothing
}  // end writeBackward