How to merge two or more cells in mvc telerik grid

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Telerik

MVC4

I have code in Controller:

[HttpPost, GridAction(EnableCustomBinding = true)]
        public ActionResult List(RegisterTeachingListModel model, GridCommand command)
        {
            if (model == null)
            {
                model = new RegisterTeachingListModel();
            }

            var registerTeaching = _registerTeachingService.Search(
                    semesterValue: model.SearchSemester,
                    sessionValue: model.SearchSession,
                    group: model.SearchGroup,
                    classOpeningId: model.SearchClassOpening,
                    fromDate: model.SearchFromDate,
                    toDate: model.SearchToDate
                    )
                .Select(x =>
                {
                    return x.ToModel();
                }).ForCommand(command);
            int on = (command.Page - 1) * command.PageSize + 1;
            var pagedList = registerTeaching.PagedForCommand(command)
                .Select(x =>
                {
                    var registerTeachingModel = x;

                    if (x.SubjectAssignmentId != 0)
                    {
                        var SubjectAssignment = ServiceFacade.SubjectAssignmentService.GetById(x.SubjectAssignmentId);
                        if (SubjectAssignment != null)
                            registerTeachingModel.SubjectName = SubjectAssignment.SubjectDeclaration.Subject.SubjectBase.Name;
                    }
                    if (x.StaffId != 0)
                    {
                        var staff = ServiceFacade.StaffService.GetById(x.StaffId);
                        if (staff != null)
                        {
                            registerTeachingModel.StaffName = staff.FullName;
                        }

                    }
                    if (x.ClassOpeningId != 0)
                    {
                        var classOpening = ServiceFacade.ClassOpeningService.GetById(x.ClassOpeningId);
                        if (classOpening != null)
                            registerTeachingModel.ClassName = classOpening.Name;
                    }
                    if (x.Course == (Course)1)
                    {
                        registerTeachingModel.IsShowing = true;
                    }


                    registerTeachingModel.ON = on++;
                    return registerTeachingModel;
                });
            model.RegisterTeachings = new GridModel<RegisterTeachingModel>
            {
                Data = pagedList,
                Total = registerTeaching.Count()
            };

            return new JsonResult { Data = model.RegisterTeachings };
        }

I have code in View:

@(Html.Telerik().Grid<Nop.Admin.Models.RegisterTeaching.RegisterTeachingModel>()
        .Name("registerTeachings-grid")
        .NoRecordsTemplate(T("Admin.Common.NoRecord").ToString())
        //set keys for model
        .ToolBar(command =>
        {
            //command.Insert();
            //command.Custom().Action("ExportExcel", "RegisterTeaching",
            //    new { /*routeValues here*/}).Text(T("Admin.Common.ExportToExcel").ToString());
        })
        .DataKeys(key =>
        {
            key.Add(model => model.Id);
        })
        //define columns in grid
        .Columns(columns =>
        {
            columns.Bound(c => c.ON)
                .Filterable(false)
                .Sortable(false)
                .HtmlAttributes(new { @class = "t-header" })
                .ReadOnly()
                .Title(T("Admin.Common.#").ToString())
                .Width(50);
            //bound column here

            columns.Bound(c => c.Date).Format("{0:dd/MM/yyyy}");
            columns.Bound(c => c.Course);
            columns.Bound(c => c.ClassOpeningId).ClientTemplate("<#= ClassName #>");
            columns.Bound(c => c.SubjectAssignmentId).ClientTemplate("<#= SubjectName #>");
            columns.Bound(c => c.StaffId).ClientTemplate("<#= StaffName #>");
            columns.Bound(c => c.PPCT);
            columns.Bound(c => c.Replace);
            columns.Bound(c => c.Preparing);
            columns.Bound(c => c.Description);
            //command columns here
            //columns.Command(commands =>
            //{
            //    commands.Edit().ButtonType(GridButtonType.Image);
            //    commands.Delete().ButtonType(GridButtonType.Image);
            //}).Width(78);
        })
                //.Editable(editing => editing.Mode(GridEditMode.PopUp).TemplateName("_CreateOrUpdate").AdditionalViewData(
                //        new
                //        {
                //            AvailableGroups = Model.AvailableGroups,
                //            AvailableLevels = Model.AvailableLevels,
                //            AvailableStaffGroups = Model.AvailableStaffGroups,
                //            AvailableSubjects = Model.AvailableSubjects
                //        })
                //    )
        .Pageable(paging => paging
            .PageSize(gridPageSize)
            .Position(GridPagerPosition.Both)
        )
        .DataBinding(dataBinding => dataBinding.Ajax()
            .Select("List", "RegisterTeaching")
            .Insert("AjaxCreate", "RegisterTeaching")
            .Update("AjaxEdit", "RegisterTeaching")
            .Delete("AjaxDelete", "RegisterTeaching")
        )
        .ClientEvents(events => events
            .OnDataBinding("onDataBinding")
        )
        .Reorderable(reordering => reordering.Columns(true))
        .Selectable()
        .KeyboardNavigation()
        .EnableCustomBinding(true)
        .Scrollable(scroll => scroll.Height("auto"))
    )

Please help me! I want to merge cell (the same to picture)
picture demo