$ perl -Mstrict -Mwarnings -E '
    my @files = "A" .. "I";
    my $items_per_page = 3;
    my $current_item = 0;

    for (@files) {
        say;
        if (not ++$current_item % $items_per_page) {
            say "Next Page" unless $current_item == @files;
        }
    }
'
A
B
C
Next Page
D
E
F
Next Page
G
H
I