计算两个正整数的和差积商
问题描述：
答
a = eval(input())
b = eval(input())
print(a,"+",b,"=",a+b)
print(a,"-",b,"=",a-b)
print(a,"*",b,"=",a*b)
if b != 0:
print(a,"/",b,"=",a//b)