private static void BuyProducts(List <Person> people, List <Product> products)
{
string command;
while ((command = Console.ReadLine()) != "END")
{
string[] token = command.Split();
string personName = token[0];
string productName = token[1];
Person person = people.First(p => p.Name == personName);
Product product = products.First(p => p.Name == productName);
string output = person.TryBuyProduct(product);
Console.WriteLine(output);
}
}