import math
import sys

class Item:
    def __init__(self, value=0, coefs=None):
        self.value = value
        self.coefs = coefs if coefs is not None else []

D = int(input())

if D == 0:
    print("! 0", flush=True)
    sys.exit(0)

F = []

for n in range(1, 11):
    print(f"? {n}", flush=True)

    value = int(input())
    coefs = []

    coef = 1
    for i in range(D + 1):
        coefs.append(coef)
        coef *= n

    F.append(Item(value, coefs))

for i in range(D, 1, -1):
    nxt = []

    for j in range(len(F)):
        for k in range(j + 1, len(F)):
            L = math.lcm(F[j].coefs[i], F[k].coefs[i])

            a = L // F[j].coefs[i]
            b = L // F[k].coefs[i]

            value = a * F[j].value - b * F[k].value
            coefs = [
                a * F[j].coefs[n] - b * F[k].coefs[n]
                for n in range(D + 1)
            ]

            nxt.append(Item(value, coefs))

    nxt = nxt[:10]
    F = nxt

L = math.lcm(F[0].coefs[0], F[1].coefs[0])

a = L // F[0].coefs[0]
b = L // F[1].coefs[0]

val = a * F[0].value - b * F[1].value
coef = a * F[0].coefs[1] - b * F[1].coefs[1]

assert coef != 0

val //= coef

print(f"! {val}", flush=True)