import math

N = int(input())

list = []

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

if N == 2:
    p = list[0]
    if p == 1:
        print("!", 11)
    elif p == 9:
        print("!", 33)
    elif p == 25:
        print("!", 55)
    elif p == 49:
        print("!", 77)
    elif p == 64:
        print("!", 88)
    elif p == 81:
        print("!", 99)
    else:
        print("!", -1)
else:
    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.isqrt(a * b // c)
        X = 10 ** (N - 1) * num
        for i in range(N - 1):
            X += list[i] // num * 10 ** i
        print("!", X)
    else:
        print("!", -1)