class Person:
    def __init__(self,name, age):
	    self.__name = name
	    self.__age = age	
    @classmethod
    def from_string(cls,person_str):
        x,y=person_str.split(",")
        obj=cls(x,y)
        return obj
    	
    def __str__(self):
        return (self.__name+" is "+str(self.__age)+" years old")