# Python 语言程序设计（2017 年秋）

1004. Average integer

Input two integers $a$ and $b$ of type int, and output average integer of $a$ and $b$.

Note: $a$ and $b$ may be very large, like $2147483647$.

If the average is not an integer, you should output the nearest integer which is, at the same time, closer to $0$.

### 样例

Input
15 20

Output
17