#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll = long long;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vvvvll = vector<vvvll>;
using vvvvvll = vector<vvvvll>;
#define all(A) A.begin(),A.end()
#define rep(i, n) for (ll i = 0; i < (ll) (n); i++)
template<class T>
bool chmax(T& p, T q, bool C = 1) {
    if (C == 0 && p == q) {
        return 1;
    }
    if (p < q) {
        p = q;
        return 1;
    }
    else {
        return 0;
    }
}

template<class T>
bool chmin(T& p, T q, bool C = 1) {
    if (C == 0 && p == q) {
        return 1;
    }
    if (p > q) {
        p = q;
        return 1;
    }
    else {
        return 0;
    }
}

ll gcd(ll(a), ll(b)) {
    if (a == 0)return b;
    if (b == 0)return a;
    ll c = a;
    while (a % b != 0) {
        c = a % b;
        a = b;
        b = c;
    }
    return b;
}
ll sqrtz(ll N) {
    ll L = 0;
    ll R = sqrt(N) + 10000;
    while (abs(R - L) > 1) {
        ll mid = (R + L) / 2;
        if (mid * mid <= N)L = mid;
        else R = mid;
    }
    return L;

}

using mint = modint1000000007;
using vm = vector<mint>;
using vvm = vector<vm>;
using vvvm = vector<vvm>;


vector<mint> fact, factinv, inv;
const ll mod = 1e9+7;
void prenCkModp(ll n) {
    fact.resize(n + 5);
    factinv.resize(n + 5);
    inv.resize(n + 5);
    fact[0] = fact[1] = 1;
    factinv[0] = factinv[1] = 1;
    inv[1] = 1;
    for (ll i = 2; i < n + 5; i++) {
        fact[i] = (fact[i - 1] * i);
        inv[i] = mod - (inv[mod % i] * (mod / i));
        factinv[i] = (factinv[i - 1] * inv[i]);
    }

}

mint nCk(ll n, ll k) {
    if (n < k||k<0) return 0;
    return fact[n] * (factinv[k] * factinv[n - k]);
}


int main() {

    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    ll N;
    cin>>N;
    vvll L(N);
    queue<ll> Q;
    rep(i,N)Q.push(i);
    ll w;
    rep(t,2){
        while(Q.size()>1){
            ll p=Q.front();
            Q.pop();
            ll q=Q.front();
            Q.pop();
            cout<<"? "<<p+1<<" "<<q+1<<endl;
            ll x;
            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;

}