#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;

#include <atcoder/all>
using namespace atcoder;

#define REP(i,n) for(int i = 0; i < (int)n; i++)
#define RREP(i,n) for(int i = (int)n-1; i >= 0; i--)
#define LREP(i,n) for(LL i = 0; i < (LL)n; i++)

#define Vi vector<int>
#define Vl vector<long long>
#define P pair<int, int>
#define LP pair<long long ,long long>
#define T3 tuple<LL, LL, LL>
#define T4 tuple<LL, LL, LL, LL>
#define INF 1000000007
#define SIZE 400010
#define MOD 998244353
typedef long long LL;

#define M 512

int N;
int A[2 * M];

int dfs(int index) {
	if (index >= M) {
		return A[index] = index - M + 1;
	}
	int res;
	int a = dfs(index * 2), b = dfs(index * 2 + 1);
	if (a > N || b > N) {
		res = min(a, b);
	}
	else {
		cout << "? " << a << " " << b << endl;
		cin >> res;
	}
	return A[index] = res;
}

int main() {
	cin >> N;
	
	int t = dfs(1);
	queue<int> que;
	int index = 1;
	while (index < M) {
		if (A[index * 2] == t) {
			que.push(A[index * 2 + 1]);
			index = index * 2;
		}
		else {
			que.push(A[index * 2]);
			index = index * 2 + 1;
		}
	}
	int a = que.front(); que.pop();
	while (que.size()) {
		int b = que.front(); que.pop();
		if (a > N || b > N) {
			a = min(a, b);
		}
		else {
			cout << "? " << a << " " << b << endl;
			cin >> a;
		}
	}
	cout << "! " << a << endl;
}