List<double> numbers = Console.ReadLine().Split(' ').Select(double.Parse).ToList();
            var counts = new SortedDictionary<double, int>();
            foreach (var num in numbers)
            {
                if (counts.ContainsKey(num))
                {
                    counts[num]++;
                }
                else {
                    counts[num] = 1;
                }
            }
            foreach (var num in counts)
            {
                Console.WriteLine("{0} -> {1}",num.Key,num.Value);
            }