import java.util.Scanner;

public class SimulationFW {
  public static void main(String[] a) {
    AtomicModel model = new VendingMachine();
    Scanner sc = new Scanner(System.in);   
    while (true) {
      String input = sc.nextLine();
      System.out.println(model.lambda());
      model.delta(input);
    }
  }
}