CountNums

using System;
using System.Collections.Generic;
using System.Linq;

namespace CountNums
{
    class Program
    {
        static void Main(string[] args)
        {
            Dictionary<int, int> dict = new Dictionary<int, int>();
            int[] nums = Console.ReadLine()
                .Split(" ", StringSplitOptions.RemoveEmptyEntries)
                .Select(int.Parse)
                .ToArray();

            foreach (var num in nums)
            {
                if (!dict.ContainsKey(num))
                {
                    dict.Add(num, 0);
                }

                dict[num]++;
            }

            foreach (var num in dict
                .OrderBy(x => x.Key))
            {
                Console.WriteLine($"{num.Key} => {num.Value}");
            }
        }
    }
}