def main():
    T = int(input())
    for _ in range(T):
        _ = input()
        S = input()
        A_idx = len(S)+1
        while len(S) > 2:
            A_idx = S.rfind("ABB", None, A_idx)
            if A_idx == -1:
                break
            S = S[:A_idx] + S[A_idx+2:]
            A_idx += 2

        print(S)


if __name__ == "__main__":
    main()