private static string ProceessSearchQueries(Dictionary<string, string> phonebook) { var contactName = Console.ReadLine(); var queriesResult = new StringBuilder(); while (!string.IsNullOrEmpty(contactName)) { var contact = phonebook.Find(contactName); queriesResult.AppendLine(contact != null ? string.Format("{0} -> {1}", contact.Key, contact.Value) : string.Format("Contact {0} does not exist.", contactName)); contactName = Console.ReadLine(); } return queriesResult.ToString(); }