private static void Main(string[] args)
        {
            int[,] array = { { 4, 0, 1 },
                             { 3, 4, 5 },
                             { 3, 5, 5 }
                           };
            int[] maxCount = new int[2];
            var countElems = new Dictionary<int, int>(array.GetLength(0));
            for (int i = 0; i < array.GetLength(0); i++)
            {
                for (int j = 0; j < array.GetLength(1); j++)
                {
                    if (!countElems.ContainsKey(array[i, j]))
                    {
                        countElems.Add(array[i, j], 1);
                    }
                    else
                    {
                        countElems[array[i, j]]++;
                    }
                    var maxSequence = countElems.Values.Max();
                    if (maxCount[1] < maxSequence)
                    {
                        maxCount[0] = i;
                        maxCount[1] = maxSequence;
                    }
                }
                countElems.Clear();
            }
            Console.WriteLine(maxCount[0]);
        }