T = int(input())
for _ in range(T):
    R = list(input())
    S = input()
    K = int(input())

    if(S[0] == "W"):
        R[:K] = ["A"] * K
        if(R[K:].count("?") > 1 or "W" in R[K:]):
            print("".join(R))
        else:
            R = [i if i != "?" else "W" for i in R]
            print("".join(R))
    else:
        if(R[:K].count("A") == K):
            print("A" * len(R))
        elif("W" in R[:K]):
            print("".join(R))
        else:
            if("W" in R):
                if(R[:K].count("?") == 1):
                    R[:K] = ["A" if R[i] == "A" else "W" for i in range(K)]
                    print("".join(R))
                else:
                    print("".join(R))
            else:
                print("".join(R))