for _ in range(int(input())):
    R = list(input())
    S = input()
    K = int(input())
    if S[0] == 'W':
        for i in range(K):
            R[i] = 'A'
        if 'W' not in R and R.count('?') == 1:
            R[R.index('?')] = 'W'
    else:
        if R[:K].count('A') == K:
            R = ['A' * len(R)]
        elif 'W' in R and R[:K].count('?') == 1 and 'W' not in R[:K]:
            R[R.index('?')] = 'W'
    print("".join(R))