public Buyer(string name, Cashbox cashbox)
{
this.name = name;
this.cashbox = cashbox;
thread = new Thread(Buy);
thread.Start();
}
static void Main(string[] args)
{
Cashbox cashbox = new Cashbox();
new Buyer("#1", cashbox);
new Buyer("#2", cashbox);
new Buyer("#3", cashbox);
new Buyer("#4", cashbox);
new Buyer("#5", cashbox);
}