def gen_ops(x: int, y: int):
    v = [0, 1, 2]
    # keep [0] = x
    ops = [(v[0], v[2], v[1])]
    for i in range(y.bit_length() - 1)[::-1]:
        ops.append((v[1], v[1], v[2]))
        if y >> i & 1:
            ops.append((v[0], v[2], v[1]))
        else:
            v[1], v[2] = v[2], v[1]
    return ops, v[1]


def check_ops(x, y):
    ops, c = gen_ops(x, y)
    v = [x, y, 0]
    for i, j, k in ops:
        if i == k or j == k:
            return False
        v[k] = v[i] + v[j]
    return v[c] == x * y


def f_print(*args):
    print(*args, flush=True)


def ask1(p: int):
    v = "ABC"[p]
    f_print("?", v)
    z = int(input())
    if z == -1:
        exit()
    return z


def ask2(p1: int, p2: int, p3: int):
    v1 = "ABC"[p1]
    v2 = "ABC"[p2]
    v3 = "ABC"[p3]
    f_print("+", v1, v2, v3)
    z = int(input())
    if z == -1:
        exit()
    return z


from collections import Counter


def get0(p: int):
    """[p] の値を調べる"""
    g0 = 2
    c = Counter()
    while True:
        z = ask1(p)
        c[z] += 1
        if c[z] >= g0:
            return z


x = get0(0)
y = get0(1)
ops, ch = gen_ops(x, y)
v = [x, y, 0]
for i, j, k in ops:
    v[k] = v[i] + v[j]
    while True:
        ask2(i, j, k)
        if get0(k) == v[k]:
            break

f_print("!", "ABC"[ch])