import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	void run() {

		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		ArrayDeque<Integer> que = new ArrayDeque<>();
		for (int i = 1; i <= N; ++i)
			que.addLast(i);
		ArrayList<Integer>[] loser = new ArrayList[N];
		for (int i = 0; i < N; ++i)
			loser[i] = new ArrayList<>();
		while (que.size() > 1) {
			ArrayDeque<Integer> next = new ArrayDeque<>();
			while (!que.isEmpty()) {
				if (que.size() >= 2) {
					int a = que.pop();
					int b = que.pop();
					System.out.println("? " + a + " " + b);
					int ans = sc.nextInt();
					next.add(ans);
					loser[ans-1].add((a ^ b) ^ ans);
				} else if (que.size() == 1) {
					next.add(que.pop());
				}
			}
			que = next;
		}
		int first = que.pop();
		for (int v : loser[first-1])
			que.addLast(v);
		// 2*n-1-n=n-1
		while (que.size() > 1) {
			ArrayDeque<Integer> next = new ArrayDeque<>();
			while (!que.isEmpty()) {
				if (que.size() >= 2) {
					System.out.println("? " + que.pop() + " " + que.pop());
					int ans = sc.nextInt();
					next.add(ans);
				} else if (que.size() == 1) {
					next.add(que.pop());
				}
			}
			que = next;
		}
		int second = que.pop();
		System.out.println("! " + second);
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}
}