#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#define popcount __builtin_popcount
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;

int main()
{
    int n; cin>>n;
    int d=1;
    while(d*d<n) d++;
    vector<int> v[20];
    for(int i=1; i<=n; i++){
        v[i%d].push_back(i);
    }
    int mxb[20];
    int ret;
    for(int i=0; i<d; i++){
        mxb[i]=v[i][0];
        for(int j=1; j<v[i].size(); j++){
            cout<<"? "<<v[i][j]<<" "<<mxb[i]<<endl;
            cin>>ret;
            if(ret==v[i][j]) mxb[i]=v[i][j];
        }
    }
    int mx=mxb[0], mx2=mxb[1];
    int mxi=0;
    cout<<"? "<<mxb[0]<<" "<<mxb[1]<<endl;
    cin>>ret;
    if(ret==mxb[1]){
        swap(mx, mx2);
        mxi=1;
    }
    for(int i=2; i<d; i++){
        cout<<"? "<<mx2<<" "<<mxb[i]<<endl;
        cin>>ret;
        if(ret==mx2) continue;
        cout<<"? "<<mx<<" "<<mxb[i]<<endl;
        cin>>ret;
        if(ret==mxb[i]){
            mx2=mx;
            mx=mxb[i];
            mxi=i;
        }else{
            mx2=mxb[i];
        }
    }
    cout<<"! "<<mx2<<endl;
    return 0;
}