#!/usr/bin/perl
print ("what is 17 plus 26?\n");
$correct_answer = 43;       # the correct answer
$input_answer = ;
chop ($input_answer);
until ($input_answer == $correct_answer) {
         print ("Wrong! Keep trying!\n");
         $input_answer = ;
         chop ($input_answer);
}
print ("You've got it!\n");