#include <bits/stdc++.h>
using namespace std;
int main() {
    int N,w,p,q,x,t=2;
    cin>>N;
    vector<vector<int>> L(N);
    queue<int> Q;
    while(N--)Q.push(N);
    while(t--){
        while(Q.size()>1){
            p=Q.front();
            Q.pop();
            q=Q.front();
            Q.pop();
            cout<<"? "<<p+1<<" "<<q+1<<endl;
            cin>>x;
            x--;
            Q.push(x);
            L[x].push_back(p+q-x);
        }
        w=Q.front();
        Q.pop();
        for(auto v:L[w])Q.push(v);
    }
    cout<<"! "<<w+1<<endl;
}