#!/usr/bin/python

import sys

# ----------------------------------------------------------------
class Observable(list):
    """
    A class of thing that can be observed.  When its notifyObservers()
    method is called with an event, it passes that event on to its
    observers.
    """

    def addObserver(self, observer):
        self.append(observer)

    def notifyObservers(self, event):
        for observer in self:
            observer.observeEvent(event)
    

# ----------------------------------------------------------------
class Observer(object):
    """
    A class of thing that observes an Observable.  The Observable will
    calls the Observer's observeEvent() method.
    """

    def __init__(self, name):
        self.name = name

    def observeEvent(self, event):
        sys.stdout.write('=== %s: "%s"\n' % (self.name, event))


# ----------------------------------------------------------------
class GoatDetector(Observable):
    """
    This class notifies all its observers if a string contains the word
    'goat'.
    """

    def detect(self, line):
        if line.find('goat') != -1:
            self.notifyObservers('goats detected')


# ----------------------------------------------------------------
class DuckDetector(Observable):
    """
    This class notifies all its observers if a string contains the word
    'duck'.
    """

    def detect(self, line):
        if line.find('duck') != -1:
            self.notifyObservers('ducks detected')

        
# MAIN -----------------------------------------------------------

goatD = GoatDetector()
duckD = DuckDetector()

alice = Observer('Alice')
bert = Observer('Bert')
chris = Observer('Chris')

goatD.addObserver(alice)
goatD.addObserver(bert)
duckD.addObserver(chris)

for line in iter(sys.stdin.readline, ""):  # iter/readline for line-buffering
    goatD.detect(line)
    duckD.detect(line)