import functools
import itertools
import math
import sys


def submit(answer: int):
    print(f"! {answer}")
    sys.exit(0)


def query(x, y):
    output = int(input(f"? {x} {y}\n"))
    if output == -1:
        sys.exit(0)
    return output


def find_last_query(candidates, n):
    for i, j in itertools.permutations(range(n - 1), r=2):
        product_to_answer = {
            candidate[n - 1 - i] * candidate[n - 1 - j]: candidate
            for candidate in candidates
        }
        if len(product_to_answer) == len(candidates):
            return sorted((i, j)), {
                key: int("".join(map(str, value)))
                for key, value in product_to_answer.items()
            }
    return None


def solve(n: int):
    assert 2 <= n
    NOT_FOUND = -1
    if n == 2:
        oks = {i**2: 11 * i for i in (1, 5, 7, 8, 9)}
        submit(oks.get(query(0, 1), NOT_FOUND))
    products = [query(i, n - 1) for i in reversed(range(n - 1))]
    gcd = functools.reduce(math.gcd, products, 0)
    candidates = []
    for first_digit in range(1, 10):
        if gcd % first_digit != 0:
            continue
        trying = [first_digit]
        trying.extend(product // first_digit for product in products)
        if all(0 <= digit <= 9 for digit in trying):
            candidates.append(trying)
    last_query = find_last_query(candidates, n)
    if last_query is None:
        submit(NOT_FOUND)
    indices, product_to_answer = last_query
    submit(product_to_answer.get(query(*indices), NOT_FOUND))


solve(int(input()))