Anagram algorithm - using string.Contains, Split functions

Anagram2.cs

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string op = "";

            int t = Convert.ToInt16(Console.ReadLine());

            for (int q = 1; q <= t; q++)
            {
                string input = Console.ReadLine();
                int count = 0;



                if (input.Length % 2 == 1)
                {
                    op += "-1\n";
                }
                else
                {
                    string a = input.Substring(0, input.Length / 2);
                    string b = input.Substring(input.Length / 2, input.Length / 2);
                    string mn = "";
                    foreach (char x in b)
                    {
                        if (!mn.Contains(x))
                        {
                            mn += x;
                        }
                    }

                    foreach (char x in mn)
                    {

                        int one = a.Split(x).Length - 1;
                        int two = b.Split(x).Length - 1;
                        if (two > one)
                        {
                            count += two - one;
                        }


                    }

                    op += count.ToString() +"\n";



                }

            }

            Console.WriteLine(op);
            Console.ReadKey();









        }
    }
}