
def jia (a,b):
    return a+b
def jian (a,b):
    return a-b
def cheng (a,b):
    return a*b
def chu (a,b):
    return a/b
while True:
    a = int(input("请输入数字>>"))
    c = input("请输入 + - * / >>")
    b = int (input("请输入数字"))
    if x == 'jia':
       print (return)
    elif x == 'jian':
	print (return)
    elif x == 'cheng':
	print (return)
    elif x == 'chu':
        print (return)


