Using SortedDictionary in C#

In C++ we have map. In C# the equivalent of map is Dictionary. However it's not sorted. So we use SortedDictionary instead. Following is an example of mapping.

using System;
using System.Collections.Generic;

namespace PracticeApp
{
    class Program
    {
        static void Main(string[] args)
        {
            var s = Console.ReadLine()?.Split('+');
            var myDictionary = new SortedDictionary<int, int>();
            foreach (var item in s)
            {
                int a = int.Parse(item);
                myDictionary.TryGetValue(a, out var x);
                myDictionary[a] = x + 1;
            }
            foreach (var item in myDictionary)
            {
                Console.WriteLine(item.Key+" "+item.Value);
            }
        }
    }
}

Sample input: 3+2+1+1+2+2+3
Sample output:
1 2
2 3
3 2