// #define DEBUGGING
#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ALL(V) (V).begin(), (V).end()
#define ALLR(V) (V).rbegin(), (V).rend()

template <typename T> using V = vector<T>;
template <typename T> using VV = V<V<T>>;
template <typename T, typename U> using P = pair<T, U>;
using ll = int64_t;
using ull = uint64_t;
using PLL = P<ll, ll>;

template <typename T> const T& var_min(const T &t) { return t; }
template <typename T> const T& var_max(const T &t) { return t; }
template <typename T, typename... Tail> const T& var_min(const T &t, const Tail&... tail) { return min(t, var_min(tail...)); }
template <typename T, typename... Tail> const T& var_max(const T &t, const Tail&... tail) { return max(t, var_max(tail...)); }
template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); }
template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); }
template <typename T> const T& clamp(const T &t, const T &low, const T &high) { return max(low, min(high, t)); }
template <typename T> void chclamp(T &t, const T &low, const T &high) { t = clamp(t, low, high); }

namespace init__ {

struct InitIO {
    InitIO() {
        cin.tie(nullptr);
        ios_base::sync_with_stdio(false);
        cout << fixed << setprecision(30);
    }
} init_io;

}

#ifdef DEBUGGING
#include "../debug.cpp"
#else
#define DEBUG(...) 0
#define DEBUG_SEPARATOR_LINE 0
#endif

template <typename T>
T make_v(T init) { return init; }

template <typename T, typename... Tail>
auto make_v(T init, size_t s, Tail... tail) {
#define rec make_v(init, tail...)
    return V<decltype(rec)>(s, rec);
#undef rec
}

ll query(ll x, ll y) {
    cout << "? " << x << ' ' << y << endl << flush;
    ll ret;
    cin >> ret;
    return ret;
}

ll rquery(ll x, ll y) {
    ll res = query(x, y);
    return res == x ? y : x;
}

int main() {
    ll N;
    cin >> N;
    V<ll> people(N);
    iota(ALL(people), 1);

    while(true) {
        if(people.size() == 2) {
            cout << "! " << rquery(people[0], people[1]) << endl << flush;
            return 0;
        } else if(people.size() == 3) {
            map<ll, ll> cnt;
            for(ll i = 0; i < 3; i++) for(ll j = i + 1; j < 3; j++) {
                cnt[query(people[i], people[j])]++;
            }
            for(auto ele : cnt) if(ele.second == 1) {
                cout << "! " << ele.first << endl;
                return 0;
            }
        }
        V<ll> tmp;
        for(ll i = 0; i + 1 < people.size(); i += 2) tmp.push_back(query(people[i], people[i + 1]));
        if(people.size() & 1) tmp.push_back(people.back());
        people = move(tmp);
    }
    return 0;
}