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
a,b,c=X,X,0
count=20
for i in range(10000):
  if i%2==0:
    while True:
      if i>0 and 2*c<=X*Y:
        print('+','C','C','B',flush=True)
        t=0
        ans=int(input())
        for j in range(5):
          print('?','B',flush=True)
          ans=int(input())
          if ans==2*c:
            t+=1
        if t>=5:
          b=2*c
          break
      else:
        print('+','A','C','B',flush=True)
        ans=int(input())
        count+=1
        t=0
        for j in range(11):
          print('?','B',flush=True)
          ans=int(input())
          if ans==a+c:
            t+=1
        if t>=7:
          b=a+c
          break
  else:
    while True:
      if 2*b<=X*Y:
        print('+','B','B','C',flush=True)
        ans=int(input())
        t=0
        for j in range(11):
          print('?','C',flush=True)
          ans=int(input())
          if ans==2*b:
            t+=1
        if t>=7:
          c=2*b
          break
      else:
        print('+','A','B','C',flush=True)
        ans=int(input())
        count+=1
        t=0
        for j in range(11):
          print('?','C',flush=True)
          ans=int(input())
          if ans==a+b:
            t+=1
        if t>=7:
          c=a+b
          break
  if b>X*Y:
    p=[1]
    print(p[1])
  if c>X*Y:
    p=[1]
    print(p[1])
  if b==X*Y:
    print('!','B',flush=True)
    exit()
  if c==X*Y:
    print('!','C',flush=True)
    exit()
if Y%2==0:
  print('!','B',flush=True)
else:
  print('!','C',flush=True)
exit()