# -*- coding: utf-8 -*-
# 选择运算规则
print('please choose the operate rules:')
print('1:addition 2:Subtraction '
'3:multiplication 4:division')
num = int(input())
print('please input a number:')
a = int(input())
print('please input another number:')
b = int(input())
# 加法
if num == 1:
print('%d' '+' '%d' '=' '%d ' % (a, b, a + b))
# 减法
elif num == 2:
print('%d' '-' '%d' '=' '%d ' % (a, b, a - b))
# 乘法
elif num == 3:
print('%d' '*' '%d' '=' '%d ' % (a, b, a * b))
# 除法
elif num == 4:
if b == 0:
print('Error!!! 0 could not be divisor')
else:
print('%d' '/' '%d' '=' '%d ' % (a, b, a / b))
else:
print('Error choice! Try again.')