Vladik and Courtesy

## 题目描述 在一次正规的比赛后Vladik和Valera分别赢得了$a$ 个糖果和$b$ 个糖果。Vladik将$1$ 个他的糖果给Valera。然后Valera将$2$ 个的糖果给Vladik，所以没有人认为他不是那么慷慨大方。接下来Vladik因为同样的原因将$3$ 个糖果给Valera。 更确切的说，每个人给对方比上一次自己收到的更多一个糖果 这种情况直到他们其中有人给不出足够的糖果为止。他们从对方那里得到的糖果不被认为是自己的。你需要直到谁是给不出糖果的人。 ### 输入格式： 输入仅一行包含两个用空格分开的整数$a,b$ （$1\leq a,b\leq10^9$ ）— 分别为Vladik和Valera的糖果数 ### 输出格式： 输出一行"Vladik"，如果是Vladik首先给不出糖果，同理或者是"Valera"。 （译者注：强烈建议好好看看说明中的样例解释的图） Translated by Khassar

At regular competition Vladik and Valera won $ a $ and $ b $ candies respectively. Vladik offered $ 1 $ his candy to Valera. After that Valera gave Vladik $ 2 $ his candies, so that no one thought that he was less generous. Vladik for same reason gave $ 3 $ candies to Valera in next turn. More formally, the guys take turns giving each other one candy more than they received in the previous turn. This continued until the moment when one of them couldn’t give the right amount of candy. Candies, which guys got from each other, they don’t consider as their own. You need to know, who is the first who can’t give the right amount of candy.

Single line of input data contains two space-separated integers $ a $ , $ b $ ( $ 1<=a,b<=10^{9} $ ) — number of Vladik and Valera candies respectively.

Pring a single line "Vladik’’ in case, if Vladik first who can’t give right amount of candy, or "Valera’’ otherwise.

1 1

Valera

7 6

Vladik

Illustration for first test case:  Illustration for second test case: