Draw Grids

题号：NC223372
时间限制：C/C++/Rust/Pascal 1秒，其他语言2秒
空间限制：C/C++/Rust/Pascal 256 M，其他语言512 M
64bit IO Format: %lld

题目描述

ZYT and LBC decided to play a game.

They will alternately do the following operation.

Pick 4 integers $a,b,c,d(1\leq a,c \leq n$ and $\ 1\leq b,d \leq m)$ , where ${ |a-c|+|b-d|=1}$ , and draw a straight segment between point ${(a,b)}$ and point ${(c,d)}$ . The segment shouldn't overlap with a segment that already exists.
In any time, the segments shouldn't form a polygon. That is, there exists no sequence of distinct points ${(x_0,y_0),(x_1,y_1),⋯,(x_{k−1},y_{k−1})}$ satisfying for each integer $0 \leq u < k$ ，there is a segment between $(x_u,y_u)$ and $(x_{ (u+1)\ \text{mod}\ k },y_{ (u+1)\ \text{mod}\ k })$ .

The player who can't perform an operation during his move loses.

Determine whether ZYT can win considering that both players play optimally and ZYT starts.

The input consists of one line containing two integers  and .

Print "YES"(without quote) if ZYT can win and "NO"(without quote) if ZYT can't.

示例1

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1 3

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NO

示例2

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2 2

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YES

It is guaranteed that .