#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
#endif
typedef long long  ll;
typedef pair<int,int> pii; typedef pair<ll,ll> pll;
const int INF = 1e9; const long long LINF = 1e18;
const int MOD = 998244353; const int MOD1 = 1e9+7;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define all(x) x.begin(), x.end()
template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}
void yorn(bool ans){cout << (ans?"Yes":"No") << endl; return;}

// しばらくはsize_tをキャストに任せてみようかな
int main(){
    int n; cin >> n;
    vector<bool> p(n,true); // probably
    //rep(i,n) p.at(i) = ;

    int nex;
    int x = -1,y = -1;
    for(int i=0;i<n;i++){
        if(x<0&&p.at(i)==true){x = i; continue;}
        if(x>=0&&p.at(i)==true){y = i; break;}
    }
    cout << "? " << x << ' ' << y << endl;
    int z; cin >> z;
    if(z==x||z==y){
            cout << "? " << x << ' ' << x << endl;
            int z2; cin >> z2;
            if(z2==x) cout << "! " << x << endl;
            else cout << "! " << y << endl;
            return 0;
    }
    p.at(x) = false; p.at(y) = false;
    nex = z;
    while(1){
        int w;
        for(int i=0;i<n;i++){
            if(i==nex) continue;
            if(p.at(i)==true){w = i; break;}
            if(i==n-1){cout << "! " << nex << endl; return 0;}
        }
        cout << "? " << nex << ' ' << w << endl;
        cin >> z;
        if(z==nex){
            cout << "! " << w << endl; return 0;
        }
        if(z==w){
            cout << "! " << nex << endl; return 0;
        }
        p.at(nex) = false; p.at(w) = false;
        if(p.at(z)==true) nex = z;
        else{
            rep(i,n) if(p.at(i)==true){nex = i; break;}
        }
    }

}