N = int(input())


def bisearch(f, n):
    l = 0
    r = n
    fl = f(l)
    fr = f(r)
    while l <= r:
        m = (l + r) // 2
        fm = f(m)
        if fm == n:
            return m
        elif fm > n:
            r = m - 1
            fr = f(r)
        else:
            l = m + 1
            fl = f(l)


def try_square_root(n2):
    return bisearch(lambda n: n * n, n2)


def solve(n):
    A = []
    I = []
    count = 0
    for i in range(n - 1):
        print(f"? {i} {n-1}")
        a = int(input())
        A.append(a)
        if a > 0:
            count += 1
            I.append(i)
    if count < 2:
        if n == 2 and A[0] == 1:
            print("11")
            return
        print("! -1")
        return
    print(f"? {I[0]} {I[1]}")
    a = int(input())

    xl = try_square_root(A[I[0]] * A[I[1]] // a)

    print("!", xl, end="")
    for i in reversed(range(n - 1)):
        print(A[i] // xl, end="")
    print()


solve(N)