from collections import defaultdict
from math import isqrt

N = int(input())

def question(a, b):
    if a > b: a, b = b, a
    print("?", a, b)
    return int(input())

def answer(x):
    print("!", x)

D = defaultdict(list)
for i in range(1, 10):
    for j in range(1, 10):
        D[i*j].append((i, j))

A = []
for i in range(N-1):
    A.append(question(i, N-1))

if A.count(0) == N-1:
    answer(-1)
elif A.count(0) == N-2:
    idx = 0
    for i in range(N-1):
        if A[i] != 0:
            idx = i
            break
    if len(D[A[idx]]) == 1:
        A.append(D[A[idx]][0][0])
        A[idx] = D[A[idx]][0][0]
        answer("".join(map(str, A[::-1])))
    else:
        answer(-1)
else:
    a, b = -1, -1
    for i in range(N-1):
        if A[i] != 0:
            if a == -1:
                a = i
            elif b == -1:
                b = i
                break
    res = question(a, b)
    A.append(isqrt((A[a]*A[b])//res))
    for i in range(N-1):
        A[i] //= A[-1]
    answer("".join(map(str, A[::-1])))