chomp(my $input = <STDIN>);
my @simMatches = qw(abcd wxyz);
my $pat        = qr/(.)..(.)/;
@simMatches = map{ @_ = /$pat/; s/$pat/$_[$input-1]/; $_ }@simMatches;
print join $", @simMatches;

__END__
$input == 1;
a w

$input == 2;
d z