#include <iostream>
#include <vector>
using namespace std;
int n,t[610] = {};
vector<int> v[310];
int query(int a, int b){
	if(a==b) return a;
	if(a==0) return b;
	if(b==0) return a;
	cout << "? " << a << " " << b << endl;
	int c; cin >> c;
	v[c].push_back(a^b^c);
	return c;
}

int build(){
	for(int i=n-1;i>0;i--){
		t[i] = query(t[i<<1],t[i<<1|1]);
	}
	return t[1];
}

void max(vector<int> &a){
	if(a.size()==1){
		cout << "! " << a[0] << endl;
		return;
	}
	int x = query(a[0],a[1]);
	for(int i=2;i<a.size();i++){
		x = query(x,a[i]);
	}
	cout << "! " << x << endl;
}

int main(){
	int i;
	cin >> n;
	for(i=0;i<n;i++){
		t[i + n] = i + 1;
	}
	int x = build();
	max(v[x]);
}