#!/usr/bin/env python3
import random

n = int(input())

d = [(-1, 0), (0, 1), (1, 0), (0, -1)]


def q(x, y):
    if x < 1 or x > n or y < 1 or y > n:
        return -1
    print("?", x, y)
    return int(input())


if n == 1: print("!", q(1, 1)), exit()

x, y = n // 2, n // 2

# Sample n random points, and start at the best one.

best = 0

# Exponentially decaying window.
window = n * 1.0
for i in range(10 * n):
    window *= 1 - 1.0 / n
    w = max(int(window), 0)
    xi = random.randint(max(1, x - w), min(n, x + w))
    yi = random.randint(max(1, y - w), min(n, y + w))
    assert 1 <= xi <= n
    assert 1 <= yi <= n
    v = q(xi, yi)
    if v > best:
        best = v
        x, y = xi, yi
print("!", best)