Выдает ошибку - C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace ConsoleApplication1
{
    class Program
    {
        
        public static void Main()
        {
            var radioStations = new Dictionary<string, RadioStation>
            {
              
                ["A"] = new RadioStation("A", 1),
                ["B"] = new RadioStation("B", 2),
                ["C"] = new RadioStation("C", 3)
            };
 
            radioStations["B"].BroadcastingFrequency = 7;
 
            foreach (KeyValuePair<string, RadioStation> pair in radioStations)
            {
                Console.WriteLine("{pair.Key}: {pair.Value.BroadcastingFrequency}");
            }
        }
    }
 
    public class RadioStation
    {
        private string name;
 
        public RadioStation(string name, long broadcastingFrequency)
        {
            Name = name;
            BroadcastingFrequency = broadcastingFrequency;
        }
 
        public string Name
        {
            get { return name; }
            set
            {
                if (string.IsNullOrEmpty(value) || value.Length > 60)
                {
                    throw new InvalidOperationException();
                }
 
                name = value;
            }
        }
 
        public long BroadcastingFrequency { get; set; }
    }
}