using System;

using System.Data;

using System.Linq;

using System.Data.DataSetExtensions;

public class Program

{

    public static void Main()

    {

        DataTable dt = new DataTable();

        dt.Columns.Add("Codigo");

        dt.Columns.Add("Descricao");

        dt.Columns.Add("Emgalagem");

        dt.Columns.Add("Separado");

        dt.Rows.Add(1010,"Celular", 12,1);

        dt.Rows.Add(1010,"Celular", 12,2);

        dt.Rows.Add(1010,"Celular", 12,3);

        dt.Rows.Add(2020,"Tablet", 8,1);

        dt.Rows.Add(2020,"Tablet", 8,2);

        dt.Rows.Add(2020,"Tablet", 8,3);

        dt.Rows.Add(2020,"Tablet", 8,4);

        dt.Rows.Add(3030,"Laptop", 6,1);

        var result = from tab in dt.AsEnumerable()

              group tab by tab["Codigo"] into groupDt

                 select new 

                  { 

                    Codigo = groupDt.Key,

                    Max=groupDt.Max((r)=> int.Parse(r["Separado"].ToString()))

                  };

        foreach(var item in result)

                Console.WriteLine(item.Codigo + ": " +item.Max);

        Console.ReadLine();

    }

}