set|lambda|reduce

#!/usr/bin/python

a=set([i for i in range(4,8)])
b=set([i for i in range(5,12)])
c= sorted(a & b)
print c


print reduce(lambda x,y:(x-1)*y,c)

def func_1(x,y):
    return (x-1)*y
print reduce(func_1,c)