CF266B.Queue at the School

During the break the schoolchildren, boys and girls, formed a queue of n people in the canteen. Initially the children stood in the order they entered the canteen. However, after a while the boys started feeling awkward for standing in front of the girls in the queue and they started letting the girls move forward each second.

Let's describe the process more precisely. Let's say that the positions in the queue are sequentially numbered by integers from 1 to n, at that the person in the position number 1 is served first. Then, if at time x a boy stands on the i-th position and a girl stands on the (i + 1)-th position, then at time x + 1 the i-th position will have a girl and the (i + 1)-th position will have a boy. The time is given in seconds.

You've got the initial position of the children, at the initial moment of time. Determine the way the queue is going to look after t seconds.

课间休息时，一群中小学生（男生和女生）在食堂排成了一个由 $n$ 人组成的队列。最初，孩子们按照进入食堂的顺序站好。然而过了一段时间后，男生们觉得站在女生前面很尴尬，于是每秒都主动让女生向前移动。

我们更精确地描述这一过程：假设队列中的位置按整数从 $1$ 到 $n$ 依次编号，其中位置 $1$ 上的人最先被服务。那么，若在时刻 $x$，第 $i$ 个位置上站着一名男生，而第 $(i+1)$ 个位置上站着一名女生，则在时刻 $x+1$，第 $i$ 个位置上将变为女生，而第 $(i+1)$ 个位置上将变为男生。时间单位为秒。

已知初始时刻孩子们的排列情况，请确定 $t$ 秒后队列的样子。

The first line contains two integers n and t (1 ≤ n, t ≤ 50), which represent the number of children in the queue and the time after which the queue will transform into the arrangement you need to find.

The next line contains string s, which represents the schoolchildren's initial arrangement. If the i-th position in the queue contains a boy, then the i-th character of string s equals "B", otherwise the i-th character equals "G".

第一行包含两个整数 $n$ 和 $t$（$1 \leq n, t \leq 50$），分别表示队列中儿童的数量，以及队列转变为所求排列所需的时间。

下一行包含字符串 $s$，表示学童的初始排列。若队列中第 $i$ 个位置为一名男孩，则字符串 $s$ 的第 $i$ 个字符为 "B"；否则（即为女孩）该字符为 "G"。

Print string a, which describes the arrangement after t seconds. If the i-th position has a boy after the needed time, then the i-th character a must equal "B", otherwise it must equal "G".

输出字符串 a，它描述了经过 t 秒后的排列情况。如果第 i 个位置在所需时间后是一个男孩，则字符串 a 的第 i 个字符必须为 "B"；否则必须为 "G"。