sub h{
#23456789_123456789_123456789_123456789_1234
eval'['.('map{[@$_,1],[@$_,-1]}'x pop).'[]]'
}

##</code><code>##

sub h{
#23456789_123456789_123456789_123456789_123
[eval(('map{[@$_,1],[@$_,-1]}'x pop).'[]')]
}

##</code><code>##

sub h{
#23456789_123456789_123456789_123456789
[eval'map{[@$_,1],[@$_,-1]}'x pop.'[]']
}

##</code><code>##

sub h{
#23456789_123456789_123456789_123456789_
[eval'map{[@$_,1],[@$_,-1]}'x$_[0].'[]']
}