C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TestLibary;

namespace ICA25
{
    class Program
    {
        static void Main(string[] args)
        {
            string sTitle;
            bool bExit = false;

            sTitle = ("ICA 25 - Times table");
            Console.WriteLine("{0,60}\n", sTitle);


            do
            {
                {
                    int[,] iFinal;
                    int iNum = GetValue("Please enter the size (4-20) of the times table: ", 4, 20);

                    Console.Write("Here is the times table for that size: \n");
                    iFinal = GenerateTT(iNum);
                    DisplayTT(iFinal);
                }
            }
            while ((YesNo("Would you like to do another? Y or N:") == "Y") && !bExit);
            bExit = true;
        }


        static public int GetValue(string s, int iMin, int iMax)
        {
            int iNum;
            Utilities.GetValue(out iNum, s, 4, 20);
            return iNum;
        }


        static public int[,] GenerateTT(int iValue)
        {
            int[,] iNum = new int[iValue, iValue];

            for (int iRow = 0; iRow < iNum.GetLength(0); iRow++)
            {
                for (int iCol = 0; iCol < iNum.GetLength(1); iCol++)
                {
                    iNum[iRow, iCol] = (iCol) * (iRow);
                }
            }
            return iNum;
        }

        static public void DisplayTT(int[,] iFinal)
            
        {
            for (int iRow = 0; iRow < iFinal.GetLength(0); iRow++)
            {
                {
                    for (int iCol = 0; iCol < iFinal.GetLength(1); iCol++)
                    {
                        Console.Write( iFinal[iRow, iCol]);
                        {
                            Console.WriteLine();
                        }
                    }
                }
            }
        }

        static public string YesNo(string sPrompt)
        {
            string stemp;

            do
            {
                Console.Write("{0}", sPrompt);
                stemp = Console.ReadLine().ToString().ToUpper();
                if (stemp == "N")
                {
                    Console.Write("Bye");
                    Console.ReadLine();

                }
                if (stemp != "Y" && stemp != "N")
                {
                    Console.Write("\nPlease answer Y or N.");
                }
            }
            while ((stemp != "Y") && (stemp != "N"));
            return stemp;
        }

    }
}

this.dataGridView1.SortCompare += new System.Windows.Forms.DataGridViewSortCompareEventHandler(this.dataGridView1_SortCompare);

</KeyValueOfPersonLikeIntensityvlZcIX2K></Value></KeyValueOfPersonArrayOfKeyValueOfPersonLikeIntensityvlZcIX2Kg_S_SinKSu></ArrayOfKeyValueOfPersonArrayOfKeyValueOfPersonLikeIntensityvlZcIX2Kg_S_SinKSu>

[DataContract]
public Class Graph<TVertex, TEdge> : Dictionary<TVertex, Dictionary<TVertex, TEdge>>

[Serializable]
public Class Graph<TVertex, TEdge> : Dictionary<TVertex, Dictionary<TVertex, TEdge>>

[DataContract]
public Class Graph<TVertex, TEdge>
{
     [DataMember]
     public Dictionary<TVertex, Dictionary<TVertex, TEdge>> GraphDict { set; get; }
}

System.Runtime.Serialization.InvalidDataContractException
  HResult=0x80131500
  Message=Type 'Graph_2019_2.PersonLikeGraph' cannot be ISerializable and have DataContractAttribute attribute.