Q=int(input())
for _ in range(Q):
  S=input()
  t=input()
  K=int(input())
  N=len(S)
  h=[0]*N
  for i in range(N):
    h[i]=S[i]
  if t[0]=='W':
    for i in range(K):
      h[i]='A'
    p=[]
    count=0
    for i in range(K,N):
      if S[i]=='W':
        count+=1
      if S[i]=='?':
        p.append(i)
    if count==0 and len(p)==1:
      pos=p[0]
      h[pos]='W'
  else:
    count=0
    for i in range(K,N):
      if S[i]=='W':
        count+=1
    p=[]
    e=0
    for i in range(K):
      if S[i]=='W':
        e+=1
      if S[i]=='?':
        p.append(i)
    if e==0 and count>0 and len(p)==1:
      pos=p[0]
      h[pos]='W'
    if e+len(p)==0:
      for i in range(K,N):
        h[i]='A'
  print(*h,sep='')