#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

void solve(){
    int N, M;
    string S, T="";
    cin >> N >> S;
    reverse(S.begin(), S.end());
    for (int i=0; i<N; i++){
        T += S[i];
        M = T.size();
        if (M > 2 && T[M-1] == 'A' && T[M-2] == 'B' && T[M-3] == 'B'){
            T.pop_back();
            T.pop_back();
        }
    }
    reverse(T.begin(), T.end());
    cout << T << endl;
}

int main(){

    int T;
    cin >> T;
    while(T){
        T--;
        solve();
    }

    return 0;
}