using System;

using System.Collections.Generic;

​

public class Solution {

​

    public static void Main(string[] args) {

        string[] strings = new string[] {"a", "b", "ba", "bca", "bda", "bdca"};

        Console.WriteLine(getMaxChain(strings));

    }

​

    public static int getMaxChain(string[] strings)

    {

        //int total=0;

        List<string> list = new List<string>(strings);

        // foreach(string s in list)

        // {

        //     if(total<getChain(s,list,1))

        //         total=getChain(s,list,1);

        // }

        return getChain("bdca",list,1);

    }

​

    public static int getChain(string s, List<string> l,int chain)

    {

        if(s.Length==1)

        {

            return chain;

        }

        else

        {

            for(int i=0;i<s.Length;i++)

            {

                string x=s.Substring(0,i)+s.Substring(i+1,s.Length-i-1);

                Console.WriteLine(x);

                if(l.Contains(x))

                {

                    chain++;

                    Console.WriteLine(chain);

                    getChain(x,l,chain);

                }

            }

            return chain+1;     

        }

    }

}