import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int t = sc.nextInt();
        StringBuilder sb = new StringBuilder();
        while (t-- > 0) {
            int n = sc.nextInt();
            StringBuilder tmp = new StringBuilder(sc.next());
            for (int i = n - 3; i >= 0; i--) {
                if (tmp.length() <= i + 2) {
                    continue;
                }
                if (tmp.charAt(i) == 'A' && tmp.charAt(i + 1) == 'B' && tmp.charAt(i + 2) == 'B') {
                    tmp.delete(i, i + 2);
                }
            }
            sb.append(tmp).append("\n");
        }
        System.out.print(sb);
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}