#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#include <iomanip>
#include <complex>
#include <bitset>
#include <stack>
using namespace std;
 
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define repl(i,s,n) for(int i=s; i<=n; ++i)
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) __typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define ktya(x) sort(all(x))
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 1e18
#define INFLL 1000000000000000007LL
#define SIZE 200105
#define REP(i,n) for(int i=0;i<(int)n;++i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()
#define mind(a,b) (a>b?b:a)
#define maxd(a,b) (a>b?a:b)
#define PI (acos(-1))
typedef vector<int> vi; typedef pair<int, int> pii; typedef vector<pair<int, int> > vpii; typedef long long ll;
typedef pair<int,ll> pill; typedef pair<ll,int> plli; 
typedef pair<double, int> pdi;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }
typedef complex<double> P;
ll MOD = 1000000007;
//ll MOD=998244353;
typedef ll Weight;
struct Edge {
	int src, dst;
	Weight weight;
};
bool operator < (const Edge &e, const Edge &f) {
	return e.weight != f.weight ? e.weight > f.weight : // !!INVERSE!!
	e.src != f.src ? e.src < f.src : e.dst < f.dst;
}
typedef vector<Edge> Edges;
int N;
ll K;
string str;
char hoge[2]={'A','B'};
int main(){
	ll KK;
	cin>>N>>KK;
	cin>>str;
	if(N==1){
		if(str[0]=='A'){
			cout<<hoge[int(KK%2)]<<endl;
		}else{
			cout<<hoge[int((KK+1)%2)]<<endl;
		}
		return 0;
	}
	string nise="";
	rep(i,N){
		nise=hoge[i%2]+nise;
	}
	for(ll x=KK;x<=KK;x++){
		string ans="";
		ll K=x;
		rep(i,N){
			if(K<0)continue;
			if(K==0){
				//i kai hanten
				for(int j=i;j<N;j++){
					if(i%2==1){
						if(str[j]=='A')ans+='B';
						else ans+='A';
					}else{
						ans+=str[j];
					}
				}
				int sz=ans.size();
				for(int j=sz;j<N;j++){
					ans+=nise[j];
				}
				cout<<ans<<endl;
				K-=1;
				//return 0;
			}
			if(str[i]==hoge[i%2]){
				if(K==1){
					ans+='B';
					for(int j=i+1;j<N;j++){
						if(i%2==1){
							if(str[j]=='A')ans+='B';
							else ans+='A';
						}else{
							ans+=str[j];
						}
					}
					int sz=ans.size();
					for(int j=sz;j<N;j++){
						ans+=nise[j];
					}
					cout<<ans<<endl;
					K-=2;
					//return 0;
				}
				K-=2;
			}else{
				K-=1;
			}
		}
		string ans2=nise;
			if(K>=0){
				if(K%2 == 1){
				
					if(N%2==1)ans2[0]='B';
					cout<<ans2<<endl;
				}else{cout<<ans2<<endl;}
			}
		}
}


Measured memory_bytes: 1316