def print_name(first, last):
    print("Hello "+first+" "+last)

print_name("sherry","hu")


def print_name(first, last):
    print("Hello "+first+" "+last)

print(print_name("sherry","hu"))


def print_name(first, last):
    print("Hello "+first+" "+last)
    return"X"

print_name("sherry","hu")


def print_name(first, last):
    print("Hello "+first+" "+last)
    return"X"

print(print_name("sherry","hu"))

def add_number(num1,num2):
    return num1+num2
    #或者
    result=num1+num2
    return result

print(add_number(4,5))