#include<bits/stdc++.h>
using namespace std;
const int N=100005;
int n;
int ch[N][2],fa[N];
int rt,u,v,G,Gmin,nn;
int siz[N];
bool vis[N];
vector<int> vec;
void dfs(int x,int p){
	siz[x]=1;
	int Gmax = 0;
	if(!vis[fa[x]] and fa[x]!=p){
		dfs(fa[x],x);
		siz[x]+=siz[fa[x]];
		Gmax=max(Gmax,siz[fa[x]]);
	}
	if(!vis[ch[x][0]] and ch[x][0]!=p){
		dfs(ch[x][0],x);
		siz[x]+=siz[ch[x][0]];
		Gmax=max(Gmax,siz[ch[x][0]]);
	}
	if(!vis[ch[x][1]] and ch[x][1]!=p){
		dfs(ch[x][1],x);
		siz[x]+=siz[ch[x][1]];
		Gmax=max(Gmax,siz[ch[x][1]]);
	}
	Gmax = max(Gmax,nn-siz[x]);
	if(Gmax < Gmin){
		Gmin = Gmax;
		G = x;
	}
//	printf("%d %d\n", x, Gmax);
	vec.push_back(x);
}
bool fnd(){
	nn=0;
	for(auto p:vec){
		if(!vis[p]) nn++;
	}
	G=rt;Gmin=0x3f3f3f3f;
	vec.clear();
	dfs(rt,0);
	if(Gmin == 0) return false;
	vec.clear();
	int GG=G;
	dfs(G,0);
	G = GG;
	return true;
}
void idfs(int x,int p){
	vis[x]=true;
	if(!vis[fa[x]] and fa[x]!=p){
		idfs(fa[x],x);
	}
	if(!vis[ch[x][0]] and ch[x][0]!=p){
		idfs(ch[x][0],x);
	}
	if(!vis[ch[x][1]] and ch[x][1]!=p){
		idfs(ch[x][1],x);
	}
}
void solve(){
	scanf("%d",&n);	
	for(int i=1;i<=n;i++) fa[i]=0;
	vec.clear();
	for(int i=1;i<=n;i++){
		scanf("%d%d",&ch[i][0],&ch[i][1]);
		fa[ch[i][0]]=i;
		fa[ch[i][1]]=i;
		vis[i]=false;
		vec.push_back(i);
	}
	vis[0]=true;
	rt = 1;
	int s;
	vector<int>vv;
	while(fnd()){
		fflush(stdout);
		s=0;
		vv.clear();
		if(!vis[fa[G]]) vv.push_back(fa[G]);
		if(!vis[ch[G][0]]) vv.push_back(ch[G][0]);
		if(!vis[ch[G][1]]) vv.push_back(ch[G][1]);
		if(vv.size()==1){
			u = vv[0];
			printf("? %d %d\n",G,u);
			fflush(stdout);
			scanf("%d",&s);
			if(s==0){
				break;
			}else{
				G = u;
				break;
			}
		}else if(vv.size()==2){
			u = vv[0];
			v = vv[1];
			printf("? %d %d\n",u,v);
			fflush(stdout);
			scanf("%d",&s);
			if(s==1){
				break;
			}
			vis[G]=true;
			if(s==0){
				idfs(v,G);
				rt = u;
			}else{
				idfs(u,G);
				rt = v;
			}
		}else{
			sort(vv.begin(), vv.end(), [&](int x, int y) {
				return siz[x] > siz[y];
			});
			u = vv[0];
			v = vv[1];
			printf("? %d %d\n",u,v);
			fflush(stdout);
			scanf("%d",&s);
			if(s==1){
				idfs(u,G);
				idfs(v,G);
				rt = G;
			}else if(s==0){
				idfs(G,u);
				rt = u;
			}else{
				idfs(G,v);
				rt = v;
			}
		}
	}
	printf("! %d\n",G);
	fflush(stdout);
}
int main(){
	int tests;
	scanf("%d",&tests);
	while(tests--){
		solve();
	}
	return 0;
}