#!/usr/bin/perl -wT
    use strict;
    my @lol = ([1,2,3],
               [1,2,3,4,5],
               [1,2,3,4,5,6,7,8],
               [1,2,3,4],
               [1,2,3,4,5,6],
              );

    my $index = 0;

    $index = $#{$lol[$index]} < $#{$lol[$_]} ? $_ : $index for 0 .. $#lol;

    print "\$aoa[$index] has the most elements\n";

    =OUTPUT
    $aoa[2] has the most elements