import sys

##入力
N = int(input())

##質問
def quenstion(K):
    print("? {}".format(K))
    sys.stdout.flush()
    return int(input())

##回答
def answer(L,R):
    print("! {} {}".format(L,R))
    sys.stdout.flush()
    exit()

a = quenstion(1)
n1 = quenstion(N-1)
if 1-a == N-1-n1:
    answer(1,N-1)

l = 1
r = N-1
while r > l + 1:
    m = (r+l)//2

    r = quenstion(m)
    if m-r == 0:
        c = m
        L,R = 1,c
        if N-c > c:
            L,R = c,N
        answer(L,R)
        
    else:
        r = m