Anagram - StringBuilder, appendLine function, and interesting to read.

Anagram6.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

class Solution {
    static void Main(String[] args)
    {
        StringBuilder results = new StringBuilder();
        int testsCount = int.Parse(Console.ReadLine());
        
        for(int i=0; i<testsCount; i++)
        {
            string word = Console.ReadLine();
            if (word.Length % 2 != 0)
            {
                results.AppendLine("-1");
                continue;
            }
            
            char[] a = word.Substring(0, word.Length/2).ToCharArray();
            char[] b = word.Substring(word.Length/2, word.Length - word.Length/2).ToCharArray();
            
            int moves = 0;
            for(int j=0; j<a.Length; j++)
            {
                int index = FirstIndexOf(b, a[j]);
                if (index == -1)
                    moves++;
                else
                    b[index] = ' ';
            }
            
            results.AppendLine(moves.ToString());
        }
        
        Console.WriteLine(results.ToString());
    }
    
    private static int FirstIndexOf(char[] arr, char x)
    {
        for(int i=0; i<arr.Length; i++)
        {
            if (arr[i] == x)
                return i;
        }
        
        return -1;
    }
}