using System;

using System.Collections.Generic;

using System.Linq;

public class GFG

{

    static public void Main()

    {

        string s = "aldshflasghdfasgfkhgasdfasdgvfyweofyewyrtyefgv";

        Console.WriteLine(NewFun(s));

    }

    static int NewFun(string a)

    {

        int count = 0;

        //   int result = 0;

        string res = "";

        var dic1 = new Dictionary<char, int>();

        var dic2 = new List<int>();

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

        {

            if (!dic1.ContainsKey(a[i]))

            {

                dic1.Add(a[i], 1);

                res = res + a[i];

                count++;

            }

            else

            {

                dic1.Clear();

                dic1.Add(a[i], 1);

​

                // if (!dic2.ContainsKey(res))

                // {

                dic2.Add(count);

               // Console.WriteLine(res + " " + count);

                count = 1;

                res = a[i].ToString();

                // }

            }

        }

​

        return dic2.Max();

​

    }

}