How can i Delimite and Group Json value on asp.net

Question

I need to delimite and categorize below json value

for ex : "sub3[+]888800" sub3 is category code and 888800 is element of category.

["sub3[+]888800","sub3[+]100000","06[+]888800","06[+]100000"]

i need to result like that

sub3 -> 888800, 100000  06 - > 888800, 100000

List<string> seledItems = this.ResetSeledItems();
        this.litDebug.Text = Newtonsoft.Json.JsonConvert.SerializeObject(seledItems);
        var json = this.litDebug.Text;
        var strs = JArray.Parse(json);

        // process the delimiter
        var items =
            from str in strs.Select(x => (string)x)
            let idx = str.IndexOf("[+]")
            select new
            {
                tag = str.Substring(0, idx),
                data = str.Substring(idx + 3)
            };
        // do the grouping
        var grps =
            from item in items
            group item by item.tag into grp
            select new
            {
                tag = grp.Key,
                items = grp.Select(x => x.data)
            };
        foreach (var grp in grps)
        {
            string tag = grp.tag.ToString();

            for(int i=0;i<=grp.items.Count-1 ; i++)   //grp.items.Count wrong.
            {
                string item = grp.items.ToString();  // not get the value.
            }
        }

how can i resolve this problem ?