#include <cstdio>
#include <iostream>
using namespace std;
const int M = 200005; 
int read()
{
	int x=0,f=1;char c;
	while((c=getchar())<'0' || c>'9') {if(c=='-') f=-1;}
	while(c>='0' && c<='9') {x=(x<<3)+(x<<1)+(c^48);c=getchar();}
	return x*f;
}
int n,k,a[M];char s[M];
signed main()
{
	n=read();k=read();scanf("%s",s+1);
	for(int i=1;i<=n;i++) a[i]=s[i]-'A';
	int t=0,p=1;k=min(k,2*n+(k&1));
	while(k--)
	{
		if(t^a[p]) t^=1,p=p%n+1;
		else a[p]^=1;
	}
	for(int i=p;i<=n;i++) putchar((a[i]^t)?'B':'A');
	for(int i=1;i<p;i++) putchar((a[i]^t)?'B':'A');
}