Magic Spheres

题意翻译

#### 题目描述 Carl 有三种类型的魔法球分别有 $a$ 个, $b$ 个, $c$ 个，他可以使任意两个相同类型的魔法球变为另一种类型的魔法球，当他三种类型的魔法球数量分别对应为 $x$ 个, $y$ 个, $z$ 个的时候可以组成魔法阵，现在请你求 Carl 能否成功组成魔法阵。 #### 输入格式 第一行输入 $3$ 个整数，分别为 $a$，$b$，$c$。 第二行输入 $3$ 个整数，分别为 $x$，$y$，$z$。 #### 输出格式 如果 Carl 可以成功组成魔法阵，输出 `Yes`。 如果 Carl 不可能成功组成魔法阵，输出 `No`。 #### 数据大小 $0\leq a,b,c,x,y,z\leq 10^6$

题目描述

Carl is a beginner magician. He has $ a $ blue, $ b $ violet and $ c $ orange magic spheres. In one move he can transform two spheres of the same color into one sphere of any other color. To make a spell that has never been seen before, he needs at least $ x $ blue, $ y $ violet and $ z $ orange spheres. Can he get them (possible, in multiple actions)?

输入输出格式

输入格式

The first line of the input contains three integers $ a $ , $ b $ and $ c $ ( $ 0<=a,b,c<=1000000 $ ) — the number of blue, violet and orange spheres that are in the magician's disposal. The second line of the input contains three integers, $ x $ , $ y $ and $ z $ ( $ 0<=x,y,z<=1000000 $ ) — the number of blue, violet and orange spheres that he needs to get.

输出格式

If the wizard is able to obtain the required numbers of spheres, print "Yes". Otherwise, print "No".

输入输出样例

输入样例 #1

4 4 0
2 1 2

输出样例 #1

Yes

输入样例 #2

5 6 1
2 7 2

输出样例 #2

No

输入样例 #3

3 3 3
2 2 2

输出样例 #3

Yes

说明

In the first sample the wizard has $ 4 $ blue and $ 4 $ violet spheres. In his first action he can turn two blue spheres into one violet one. After that he will have $ 2 $ blue and $ 5 $ violet spheres. Then he turns $ 4 $ violet spheres into $ 2 $ orange spheres and he ends up with $ 2 $ blue, $ 1 $ violet and $ 2 $ orange spheres, which is exactly what he needs.