class Person:
    """ People with names. """
    
    population = 0
    
    def __init__(self, name="John Smith"):
        self.name = name
        Person.population = Person.population + 1

    def get_name(self):
        return self.name
    
    def set_name(self, newname):
    	self.name = newname
    
    def __str__(self):
        return "Person: " + self.name

def main():
    fred = Person("Fred")
    sally = Person("Sally")
    generic = Person()
    print fred
    print sally
    print generic
    generic.set_name("Bill")
    print "new name: " + str(generic)

    print "total population is " + str(Person.population)

main()