#pragma GCC optimize ("O3")
#ifdef LOCAL111
	#define _GLIBCXX_DEBUG
#else
	#define NDEBUG
#endif
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
const int INF = 1e9;
using namespace std;
template<typename T, typename U> ostream& operator<< (ostream& os, const pair<T,U>& p) { os << '(' << p.first << ' ' << p.second << ')'; return os; }

#define endl '\n'
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#ifdef LOCAL111
	#define DEBUG(x) cout<<#x<<": "<<(x)<<endl
	template<typename T> void dpite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;}
#else
	#define DEBUG(x) true
	template<typename T> void dpite(T a, T b){ return; }
#endif
#define F first
#define S second
#define SNP string::npos
#define WRC(hoge) cout << "Case #" << (hoge)+1 << ": "
template<typename T> void pite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}
template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}

template<typename T>
vector<T> make_v(size_t a){return vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
  return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

template<typename T,typename U,typename... V>
typename enable_if<is_same<T, U>::value!=0>::type
fill_v(U &u,const V... v){u=U(v...);}

template<typename T,typename U,typename... V>
typename enable_if<is_same<T, U>::value==0>::type
fill_v(U &u,const V... v){
  for(auto &e:u) fill_v<T>(e,v...);
}

const array<int, 4> dx = {0, 1, 0, -1};
const array<int, 4> dy = {1, 0, -1, 0};


typedef long long int LL;
typedef unsigned long long ULL;
typedef pair<int,int> P;

void ios_init(){
	cout.setf(ios::fixed);
	cout.precision(12);
#ifdef LOCAL111
	return;
#endif
	ios::sync_with_stdio(false); cin.tie(0);
}

int query(int x, int y) {
	cout << "? " << x + 1 << ' ' << y + 1 << endl;
	int res;
	cin >> res;
	return res - 1;
}

void answer(int x) {
	cout << "! " << x + 1 << endl;
}

int main()
{
	int n;
	cin >> n;
	int n2 = 1;
	while(n2 < n) {
		n2 *= 2;
	}
	vector<int> nodes(n2 * 2 - 1, -1);
	REP(i, n) {
		nodes[n2 - 1 + i] = i;
	}
	RREP(i, n2 - 1) {
		int l = 2 * i + 1;
		int r = 2 * i + 2;
		if(nodes[l] != -1 && nodes[r] != -1) {
			nodes[i] = query(nodes[l], nodes[r]);
		} else if(nodes[l] != -1) {
			nodes[i] = nodes[l];
		}
	}
	vector<int> ans_c;
	int p = 0;
	while(p < n2 - 1) {
		int l = 2 * p + 1;
		int r = 2 * p + 2;
		if(nodes[l] == nodes[p]) {
			if(nodes[r] != -1) {
				ans_c.push_back(nodes[r]);
			}
			p = l;
		} else {
			if(nodes[l] != -1) {
				ans_c.push_back(nodes[l]);
			}
			p = r;
		}
	}
	int ans = ans_c[0];
	FOR(i, 1, SZ(ans_c)) {
		ans = query(ans, ans_c[i]);
	}
	answer(ans);
}