#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define limit(x,l,r) max(l,min(x,r))
#define lims(x,l,r) (x = max(l,min(x,r)))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cout<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
typedef vector<T> vt;
inline int getInt() { int x; scanf("%d",&x); return x;}
template<typename T>inline istream& operator>>(istream&i,v(T)&v)
{rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v)
{stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>inline ostream& operator<<(ostream&o,const v(T)&v)
{if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>inline istream& operator>>(istream&i,pair<T1,T2>&v)
{return i>>v.fi>>v.se;}
template<typename T1,typename T2>inline ostream& operator<<(ostream&o,const pair<T1,T2>&v)
{return o<<v.fi<<","<<v.se;}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
const int MX = 200005;

// Run Length Encoding
namespace RLE {
  vp f(const vi& a) {
    if (!sz(a)) return vp();
    vp res(1,P(a[0],1));
    for (int i = 1; i < sz(a); ++i) {
      if (res.back().fi == a[i]) res.back().se++;
      else res.eb(a[i],1);
    }
    return res;
  }
  typedef pair<char,int> CP;
  v(CP) f(const string& a) {
    if (!sz(a)) return v(CP)();
    v(CP) res(1,CP(a[0],1));
    for (int i = 1; i < sz(a); ++i) {
      if (res.back().fi == a[i]) res.back().se++;
      else res.eb(a[i],1);
    }
    return res;
  }
};


int main() {
  int n,k;
  scanf("%d%d",&n,&k);
  string s;
  cin>>s;

  /*
  set<string> st;
  while (!st.count(s)) {
    st.insert(s);
    int j = 0;
    int sg = 1;
    while (0 <= j && j < n) {
      if (s[j] == 'A') {
        s[j] = 'B';
        sg = -sg;
      } else {
        s[j] = 'A';
      }
      j += sg;
    }
    cout<<s<<endl;
  }
  return 0;
  //*/

  auto d_ = RLE::f(s);
  vi d;
  drep(i,sz(d_)) d.pb(d_[i].se);
  if (s.back() == 'B') d[0]++;
  bool l = s[0]=='A';
  while (k) {
    if (!sz(d)) break;
    --k;
    if (l) {
      d.back()--;
      if (d.back()) d.pb(1);
      else {
        d.pop_back();
        if (sz(d)) d.back()++;
        else k %= 2, d.pb(2);
      }
      l = false;
    } else {
      d.back()--;
      if (d.back()) l = true;
      else d.pop_back();
    }
  }
  string ans;
  rep(i,n) {
    ans += l?'A':'B';
    if (sz(d)) {
      d.back()--;
      if (d.back() == 0) d.pop_back(), l = !l;
    } else l = !l;
  }
  cout<<ans<<endl;
  return 0;
}






















Measured memory_bytes: 3956