my @array = (
    [ qw/ 1 1 1 1 1 / ],
    [ qw/ 0 1 1 0 0 / ],
    [ qw/ 0 0 0 0 1 / ],
    [ qw/ 0 0 0 0 0 / ],
    [ qw/ 0 1 0 1 0 / ],
);
say first_allzero_row_a(\@array);
say first_allzero_row_b(\@array);