v=[0]*900
for _ in range(10):
  print('?','A',flush=True)
  ans=int(input())
  if ans<900:
    v[ans]+=1
p=max(v)
X=-1
for i in range(900):
  if v[i]==p:
    X=i
v=[0]*900
for _ in range(10):
  print('?','B',flush=True)
  ans=int(input())
  if ans<900:
    v[ans]+=1
p=max(v)
Y=-1
for i in range(900):
  if v[i]==p:
    Y=i
for i in range(Y):
  if i%2==0:
    while True:
      print('+','A','C','B',flush=True)
      ans=int(input())
      if ans==-1:
        exit()
      print('?','B',flush=True)
      ans=int(input())
      a=max(1,i)
      if ans==a*X:
        break
  else:
    while True:
      print('+','A','B','C',flush=True)
      ans=int(input())
      if ans==-1:
        exit()
      print('?','C',flush=True)
      ans=int(input())
      if ans==i*X:
        break
if Y%2==1:
  print('!','B',flush=True)
else:
  print('!','C',flush=True)
exit()