Mixed phones -Split(new[] {' ', ':'}, StringSplitOptions.Rem

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//You will be given several phone entries, in the form of strings in format:
//{firstElement} : {secondElement}
//The first element is usually the person’s name, and the second one – his phone number. The phone number consists ONLY of digits, //while the person’s name can consist of any ASCII characters.
//Sometimes the phone operator gets distracted by the Minesweeper she plays all day, and gives you first the phone, and then the name. //e.g. : 0888888888 : Pesho. You must store them correctly, even in those cases.
//When you receive the command “Over”, you are to print all names you’ve stored with their phones. The names must be printed in //alphabetical order.

namespace Mixed_phones
{
    class Program
    {
        static void Main(string[] args)
        {
            SortedDictionary<string, long> phonebook = new SortedDictionary<string, long>();
            string input = Console.ReadLine();

            while (input != "Over")
            {
                string[] phones = input.Split(new[] {' ', ':'}, StringSplitOptions.RemoveEmptyEntries).ToArray();

                string name = phones[0];
                string number = phones[1];
                bool isNumberNumber = number.All(char.IsDigit);
                bool isNumberName = name.All(char.IsDigit);

                if (!isNumberName && isNumberNumber)
                {
                    phonebook[name] = long.Parse(number);
                }
                else if (isNumberName && !isNumberNumber)
                {
                    phonebook[number] = long.Parse(name);
                }
                input = Console.ReadLine();
            }
            foreach (KeyValuePair<string, long> item in phonebook)
            {
                Console.WriteLine($"{item.Key} -> {item.Value}");
            }
        }
    }
}