private void AddCity()
 {
     try
     {
         int symbol = ReadInt("Please input city symbol:");
         Console.WriteLine("Please input city name:");
         string name = Console.ReadLine();
         manager.AddCity(new City {
             Symbol = symbol, Name = name
         });
     }
     catch (Exception ex)
     {
         Console.WriteLine($"Error adding city: {ex}");
     }
 }