Cards

题意翻译

1. 初始分数为0 1. 对于每一段连续'o',如果长度为$x$，那么你的得分为$x^2$ 1. 对于每一段连续'x',如果长度为$x$，那么你的得分为$-x^2$ 例如"ooxoooxx"得分为 $2^2-1^2+3^2-2^2+1^1=9$ 现在输入a和b，分别表示'o'的数量和'x'的数量，求一个序列，使得分最大。 你需要在第一行输出最大得分，第二行输出你排出来的序列，有多个答案时输出任意一个（special judge）。

题目描述

User ainta loves to play with cards. He has $ a $ cards containing letter "o" and $ b $ cards containing letter "x". He arranges the cards in a row, and calculates the score of the deck by the formula below. 1. At first, the score is $ 0 $ . 2. For each block of contiguous "o"s with length $ x $ the score increases by $ x^{2} $ . 3. For each block of contiguous "x"s with length $ y $ the score decreases by $ y^{2} $ . For example, if $ a=6,b=3 $ and ainta have arranged the cards in the order, that is described by string "ooxoooxxo", the score of the deck equals $ 2^{2}-1^{2}+3^{2}-2^{2}+1^{2}=9 $ . That is because the deck has 5 blocks in total: "oo", "x", "ooo", "xx", "o". User ainta likes big numbers, so he wants to maximize the score with the given cards. Help ainta make the score as big as possible. Note, that he has to arrange all his cards.

输入输出格式

输入格式

The first line contains two space-separated integers $ a $ and $ b $ ( $ 0<=a,b<=10^{5}; a+b>=1 $ ) — the number of "o" cards and the number of "x" cards.

输出格式

In the first line print a single integer $ v $ — the maximum score that ainta can obtain. In the second line print $ a+b $ characters describing the deck. If the $ k $ -th card of the deck contains "o", the $ k $ -th character must be "o". If the $ k $ -th card of the deck contains "x", the $ k $ -th character must be "x". The number of "o" characters must be equal to $ a $ , and the number of "x " characters must be equal to $ b $ . If there are many ways to maximize $ v $ , print any. Please, do not write the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

输入输出样例

输入样例 #1

2 3

输出样例 #1

-1
xoxox

输入样例 #2

4 0

输出样例 #2

16
oooo

输入样例 #3

0 4

输出样例 #3

-16
xxxx