#编写函数
#方法一
plus =lambda x: lambda y:x+y
minus = lambda x:lambda y:x-y
times=lambda x:lambda y:x*y
dividedBy=lambda x:lambda y:y//x
#????????????????下面没懂呀???????
zero,one,two,three,four,five,six,seven,eight,nine= \
map(lambda x:lambda y=None:y(x) if y else x,range(10))
print(four(dividedBy(two())))
print(seven(times(five())))
print(four(plus(nine())))
print(eight(minus(three())))
#编写函数计算
#方法二
def plus(y): return lambda x:x+y
def minus(y):return lambda x:x-y
def times(y):return lambda x:x*y
def divided_by(y): return lambda x:x/y
def zero(f=None):return 0 if not f else f(0)
def one(f=None):return 1 if not f else f(1)
def two(f=None):return 2 if not f else f(2)
def three(f=None):return 3 if not f else f(3)
def four(f=None):return 4 if not f else f(4)
def five(f=None):return 5 if not f else f(5)
def six(f=None):return 6 if not f else f(6)
def seven(f=None):return 7 if not f else f(7)
def eight(f=None):return 8 if not f else f(8)
def nine(f=None):return 9 if not f else f(9)
print(four(dividedBy(two())))
print(seven(times(five())))
print(four(plus(nine())))
print(eight(minus(three())))