class Person:
    def __init__(self,name, age):
        self.__name = name
        self.__age = age
    def __str__(self):
        return("%s is %s years old" %(self.__name,self.__age))
    @classmethod
    def from_string(cls,person_str):
        l=person_str.split(",")
        cls.__name=l[0]
        cls.__age=int(l[1])
        p=Person(cls.__name,cls.__age)
        return(p)