import math

N = int(input())

list = []

for a in range (N - 1):
    print("?", a, N - 1)
    list.append(int(input()))

p = []
i = []
for j in range(len(list)):
    if list[j] != 0:
        p.append(list[j])
        i.append(j)
        if len(p) == 2:
            break

if len(p) == 2:
    print("?", i[0], i[1])
    [a, b] = p
    c = int(input())
    num = math.sqrt(a * b / c)
    X = 10 ** (N - 1) * num
    for i in range(N - 1):
        X += list[i] / num * 10 ** i
    print("!", int(X))
elif len(p) == 1:
    [a] = p
    num = math.sqrt(a)
    if num in [1, 3, 5, 7, 8, 9]:
        X = 10 ** (N - 1) * num
        for i in range(N - 1):
            X += list[i] / num * 10 ** i
        print("!", int(X))
    else:
        print("!", -1)
else:
    print("!", -1)