$_ = "aaaabbbbcccc";
if ( not /^(\w\w)(\w\w)(\w\w)$/ ) {
    if ( not /^(\w\w)\w\w(\w\w)\w\w(\w\w)\w\w$/ ) {
        die "failed";
    }
}
print "$_ = $1 $2 $3\n";

##</code><code>##

$_ = "aaaabbbbcccc";
if ( not /^(\w\w)\w\w(\w\w)\w\w(\w\w)\w\w$/ ) {
    die "failed";
}
print "$_ = $1 $2 $3\n";