Module Module1

    Sub Main()

        Dim table As New DataTable
        table.Columns.Add("A",GetType(Integer))
        table.Columns.Add("B",GetType(Integer))
        table.Columns.Add("C",GetType(Integer))
        table.Columns.Add("S",GetType(Integer))
        table.Columns.Add("S1",GetType(Integer))
        table.Columns.Add("S2",GetType(Integer))
        table.Rows.Add(1,1,1)
        table.Rows.Add(1,2,3,DBNull.Value)
        table.Rows.Add(1,4,5,DBNull.Value,1)
        table.Rows.Add(2,6,7,8,9,DBNull.Value)
        table.Rows.Add(2,11)

        Dim temp = From p In table.AsEnumerable
                                    Group p By Key = New With {Key .A = p("A"),Key .B = p("B"),Key .C = p("C")} Into g = Group
                                    Select New With {
                                        .key = Key,_
                                        .Suryo1 = g.Sum(Function(x) If(IsDBNull(x("S")),x("S")))
                                    }

        Dim a = temp.ToList()
        Dim s = ""
    End Sub

End Module