测评会员优惠活动进行中 · 开通 VIP,有效期内测评不限次 VIP 优惠中 · 测评不限次 立即查看

A9931. Mike and Fish

编程题 普及/提高-

题目描述

As everyone knows, bears love fish. But Mike is a strange bear; He hates fish! The even more strange thing about him is he has an infinite number of blue and red fish.

![](/uploads/acgo/image/ecccd17240c9450b_ee61a7f0838e.jpeg)He has marked $n$ distinct points in the plane. $i$ -th point is point $(x_{i},y_{i})$ . He wants to put exactly one fish in each of these points such that the difference between the number of red fish and the blue fish on each horizontal or vertical line is at most 1.

He can't find a way to perform that! Please help him.

输入格式

The first line of input contains integer $n$ ( $1<=n<=2×10^{5}$ ).

The next $n$ lines contain the information about the points, $i$ -th line contains two integers $x_{i}$ and $y_{i}$ ( $1<=x_{i},y_{i}<=2×10^{5}$ ), the $i$ -th point coordinates.

It is guaranteed that there is at least one valid answer.

输出格式

Print the answer as a sequence of $n$ characters 'r' (for red) or 'b' (for blue) where $i$ -th character denotes the color of the fish in the $i$ -th point.

输入输出样例

输入 #1
4
1 1
1 2
2 1
2 2
输出 #1
brrb
输入 #2
3
1 1
1 2
2 1
输出 #2
brr
上一题 去做题 下一题