Magic Strings Alternative

using System;
using System.Collections.Generic;

public class MagicStrings
{
    static void Main()
    {
        int diff = int.Parse(Console.ReadLine());

        Dictionary<char, int> values = new Dictionary<char, int>();
        values.Add('k', 1);
        values.Add('n', 4);
        values.Add('p', 5);
        values.Add('s', 3);

        string firstSequence = string.Empty;
        string secondSequence = string.Empty;
        int firstSum = 0;
        int secondSum = 0;
        bool found = false;

        if (diff > 16)
        {
            Console.WriteLine("No");
            return;
        }

        foreach (KeyValuePair<char, int> first in values)
        {
            foreach (KeyValuePair<char, int> second in values)
            {
                foreach (KeyValuePair<char, int> third in values)
                {
                    foreach (KeyValuePair<char, int> fourth in values)
                    {
                        firstSequence = Convert.ToString(first.Key) + second.Key + third.Key + fourth.Key;
                        firstSum = first.Value + second.Value + third.Value + fourth.Value;

                        // end first 4 digits
                        foreach (KeyValuePair<char, int> fifth in values)
                        {
                            foreach (KeyValuePair<char, int> sixth in values)
                            {
                                foreach (KeyValuePair<char, int> seventh in values)
                                {
                                    foreach (KeyValuePair<char, int> eighth in values)
                                    {
                                        secondSequence = Convert.ToString(fifth.Key) + sixth.Key + seventh.Key + eighth.Key;
                                        secondSum = fifth.Value + sixth.Value + seventh.Value + eighth.Value;

                                        if (Math.Abs(firstSum - secondSum) == diff)
                                        {
                                            Console.WriteLine(firstSequence + secondSequence);
                                            found = true;
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
        if (found == false)
        {
            Console.WriteLine("No");
        }
    }
}