use warnings;
use strict;

sub menu   {
  print <<'EOM';
What would you like to do?
 1) FLASHCARD MODE
 2) TEST MODE
 3) OPTIONS
 4) Exit
EOM
} 

sub really {
  print "Are you sure? ";
  my $input = <STDIN>;
  return $input =~ /^y/i;
}

sub prompt {
  print "> ";
}

sub main {
  print "Welcome to Multiplication Challenge\n\n";
  menu(); prompt();
  while (my $input = <STDIN>) {
    print "$1\n" if $input =~ /^([123])/;
    last if $input =~ /^4/ && really();
    menu(); prompt();
  }
  print "done.\n";
}

main();