sub foo {
    my ($tuples) = @_;
    # über alle tupel iterieren
    for my $tuple (@$tuples) {
        my $first = $tuple->[0];
        my ($first, $second) = @$tuple;
    }

    say $tuples->[23]->[0]; # wert eins aus tupel nummer 24
}

my $all_tuples = [ [2,3], [7,8], [101,102], ... ];
foo($all_tuples);