use warnings;
use strict;

for my $i (1 .. 5) {
    for my $shirt (qw(T S L H)) {
        for my $size (qw(S M L XL 2X)) {
            for my $col (qw(BLU GRN WHT BLK)) {
                print 'SKU', $i, $shirt, $size, $col, "\n";
            }
        }
    }
}