Count checkboxes with other

<script type="text/javascript">
jQuery(document).ready(function($){
    $('input[name="item_meta[643][]"], input[name="item_meta[643][other_2]"]').change(function(){
    var val1 = $("input[name='item_meta[643][]']:checked").length,
        val2 = $("input[name='item_meta[643][]']:checked") ? 1 : 0,
        tot_count = val1 + val2;
    $("#field_wzfsfs").val(tot_count);
    $("#field_wzfsfs").change();
    });
});
</script>