Palindrome

using System;
using System.Globalization;
using System.Runtime.InteropServices;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            char[] input = Console.ReadLine().ToCharArray();
            Array.Sort(input);

            int singleCounter = 0;
            int indexSingle = input.Length-1;
            char before = input[0];
            bool madeCouple = false;
            bool even = false;
            bool successful = false;
            //Even
            if (input.Length % 2 == 0)
            {
                even = true;
                for (int i = 1; i < input.Length; i++)
                {
                    if (madeCouple)
                    {
                        before = input[i];
                        madeCouple = false;
                    }
                    else
                    {
                        char now = input[i];
                        if (now == before)
                        {
                            madeCouple = true;
                        }
                        else
                        {
                            Console.WriteLine("No");
                            return;
                        }
                    }
                }
                Console.WriteLine("Yes");
                successful = true;
            }
            //Odd
            else
            {
                for (int i = 1; i < input.Length; i++)
                {
                    if (madeCouple)
                    {
                        before = input[i];
                        madeCouple = false;
                    }
                    else
                    {
                        char now = input[i];
                        if (now == before)
                        {
                            madeCouple = true;
                        }
                        else
                        {
                            before = input[i];
                            indexSingle = i-1;
                            singleCounter++;
                        }
                    }
                }

                if (singleCounter > 1)
                {
                    Console.WriteLine("No");
                }
                else
                {
                    Console.WriteLine("Yes");
                    successful = true;
                }
            }

            if (successful)
            {
                char[] palindrome = new char[input.Length];
                if (even)
                {
                    int counter = 0;
                    for (int i = 0; i < palindrome.Length; i++)
                    {
                        if (i % 2 == 0)
                        {
                            palindrome[counter] = input[i];
                            counter++;
                        }
                        else
                        {
                            palindrome[^counter] = input[i];
                        }
                    }
                }
                else
                {
                    int counter = 0;
                    int iCounter = 0;
                    for (int i = 0; i < palindrome.Length; i++)
                    {
                        if (indexSingle == i)
                        {
                            int index = palindrome.Length / 2 ;
                            palindrome[index] = input[i];
                            continue;
                        }
                        if (iCounter % 2 == 0)
                        {
                            palindrome[counter] = input[i];
                            counter++;
                        }
                        else
                        {
                            palindrome[^counter] = input[i];
                        }

                        iCounter++;
                    }
                }

                foreach (var letter in palindrome)
                {
                    Console.Write(letter);
                }
            }
        }
    }
}