class Person:
    def __init__(self,name, age):
        #fill your code
        self.__name=name
        self.__age=age
    
		
    @classmethod
    def from_string(cls, person_str):
		#fill your code
        a,b=map(str,person_str.split(','))
        return '{} is {} years old'.format(a,b)
        
    def __str__(self):
		#fill your code
        return '{} is {} years old'.format(self.__name,self.__age)