#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int N;
    cin >> N;
    vector<queue<int>> tb(N + 1);
    queue<int> que;
    for(int i = 1; i <= N; i++) que.emplace(i);
    while(que.size() > 1){
        int v, u, res;
        v = que.front();
        que.pop();
        u = que.front();
        que.pop();
        cout << "? " << v << ' ' << u << endl;
        cin >> res;
        tb[res].emplace(v ^ u ^ res);
        que.emplace(res);
    }
    swap(que, tb[que.front()]);
    while(que.size() > 1){
        int v, u, res;
        v = que.front();
        que.pop();
        u = que.front();
        que.pop();
        cout << "? " << v << ' ' << u << endl;
        cin >> res;
        que.emplace(res);
    }
    cout << "! " << que.front() << endl;
}