#! perl -slw
use strict;
use Data::Dump qw[ pp ];

my @out;
while( <DATA> ) {
    chomp;
    my $n = 0;
    $out[ $n++ ] .= $_ for unpack '(A2)*', $_;
}

pp \@out;

__DATA__
abcdef
abcdef
abcdef
abcdef

##</code><code>##

C:\test>junk.pl
["abababab", "cdcdcdcd", "efefefef"]