using System;

using System.Collections.Generic;

namespace Exercise

{

    static class Program

    {

        static public void Main()

        {

            var _results = new Dictionary<string, List<string>>

            {

                {"a", new List<string> { "x", "y", "z" }},

                {"b", new List<string> { "x", "y" }},

                {"c", new List<string> { "x"}},

            };

            foreach (KeyValuePair<string, List<string>> item in _results)

            {

                Console.WriteLine($"{item.Key}: {item.Value.Count}");

            }

        }

    }

}