def binary_search(f):
    left,right=0,10**6+1
    while right-left>1:
        mid=(right+left)//2
        if f(mid):
            left=mid
        else:
            right=mid
    return left

a = 99999
def ask(x,x_d):
    print('?', x_d)
    return int(input())
    if abs(a-x) >= abs(a-x_d):
        print("1")
        return 1
    return 0

def f(x):
    s_d = x-(s-x)
    if s_d < 0:
        s_d -= 1
    else:
        s_d += 1
    r=ask(s,s_d)
    if r == 1:
        return False
    return True



s = 10**6
print('?', s)
a=binary_search(f)
print('!', a)