dict ref advanced

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

namespace _05NestedDictionariesExcercisesDic_RefAdvanced
{
    class Program
    {
        static void Main(string[] args)
        {
            Dictionary<string, List<int>> data = new Dictionary<string, List<int>>();

            string input = Console.ReadLine();

            while(input!="end")
            {

                string []inputTokens = input.Split(new string[] { "->" }
                , StringSplitOptions.RemoveEmptyEntries).ToArray();

                string name = inputTokens[0];

                if(IsName(inputTokens[1]))
                {

                    string otherName = inputTokens[1];

                    if(data.ContainsKey(otherName))
                    {
                        List<int> otherNumbers = data[otherName];


                        if(!data.ContainsKey(name))
                        {
                            data.Add(name, new List<int>());
                        }

                        data[name].Clear();
                        data[name].AddRange(otherNumbers);
                    }



                }
                else
                {
                    int[] numbers = inputTokens[1].Split(new string[] { ", " }
                    , StringSplitOptions.RemoveEmptyEntries)
                        .Select(int.Parse).ToArray();

                    if (!data.ContainsKey(name))
                    {
                        data.Add(name, new List<int>());

                    }
                    data[name].AddRange(numbers);
                }

            input = Console.ReadLine();

            }
            foreach (KeyValuePair<string,List<int>> item in data)
            {
                string name = item.Key;
                List<int> num = item.Value;
                Console.WriteLine($"{name}=== {string.Join(", ",num)}");
            }


        }
        static bool IsName(string input)
        {
            foreach (char ch in input)
            {

                if (char.IsLetter(ch))
                {
                    return true;
                }

            }
            return false;
        }

    }

}