static string SkirtingosRaidesTekste(string[] eilutes)
        {
            string rezultatas = "";
            string rezas = "";
            string raides = "aąbcčdeęėfghiįyjklmnoprsštuūųvzžw";
            for (int i = 0; i < eilutes.Length; i++)
            {
                eilutes[i].ToLower();

                for (int j = 0; j < raides.Length; j++)
                    if (eilutes[i].Contains(raides[j]))
                    {
                        rezultatas += raides[j];
                    }
            }
            for (int i = 0; i < raides.Length; i++)
            {
                if (rezultatas.Contains(raides[i]))
                {
                    rezas += raides[i];
                }
            }
                return rezas;
        }
        static char DazniausiaiPasikartojantiRaide(string[] eilutes, ref int max)
        {
            string raides = "aąbcčdeęėfghiįyjklmnoprsštuūųvzžw";
            List<int> kiekradau = new List<int>();
            max = 0;
            char raide = ' ';
            for (int i = 0; i < raides.Length; i++)
            {
                int kiekis = 0;
                for (int j = 0; j < eilutes.Length; j++)
                {
                    for (int jj = 0; jj < eilutes[j].Length; jj++)
                    {
                        if (eilutes[j].ToLower()[jj] == raides[i])
                        {
                            kiekis++;
                        }
                    }
                }
                kiekradau.Add(kiekis);
            }
            for (int i = 0; i < kiekradau.Count; i++)
            {
                if (max < kiekradau[i])
                {
                    max = kiekradau[i];
                    raide = raides[i];
                }
            }
            return raide;
        }