UNIT 42.8

def html_tag(tag_name):

    def real_decorator(func):

        def wrapper():

            print('<{0}>{1}</{0}>'.format(tag_name, func))

            return

        return wrapper

    return real_decorator
a, b = input().split()

@html_tag(a)
@html_tag(b)
def hello():
    return 'Hello, world!'

print(hello())