#include <bits/stdc++.h>

using namespace std;   const int N = 1e5+10;

int main(){
	int t, n, x, o;   cin >> t;
	static int l[N], r[N];   static bool a[N];
	while(t--){
		cin >> n;
		for(int i = 1; i <= n; i++)
			cin >> l[i] >> r[i], a[l[i]] = a[r[i]] = 1;
		for(int i = 1; i <= n; i++) if(!a[i]) {x = i; break;}
		while(1){
			if(l[x] && r[x]){
				cout << "? " << l[x] << ' ' << r[x] << '\n';
				cout.flush();   cin >> o;
				if(o == 1) break;   else x = (!o ? l[x] : r[x]);
			}
			else if(l[x] && !r[x]){
				cout << "? " << l[x] << ' ' << x << '\n';
				cout.flush();   cin >> o;
				if(o == 2) break;   else x = l[x];
			}
			else if(!l[x] && r[x]){
				cout << "? " << r[x] << ' ' << x << '\n';
				cout.flush();   cin >> o;
				if(o == 2) break;   else x = r[x];
			}
			else break;
		}
		cout << "! " << x << '\n';   cout.flush();
		for(int i = 1; i <= n; i++) l[i] = r[i] = a[i] = 0;
	}
	return 0;
}