#include<bits/stdc++.h>
using namespace std;
const int N=100005;
int n;
int ch[N][2],fa[N];
int rt,u,v;
int dis1[N],dis2[N];
bool vis[N];
vector<int> vec;
void dfs(int x,int d,int *dis){
	dis[x]=d;
	if(dis[x]>dis[u]) u=x;
	if(!vis[fa[x]] and !dis[fa[x]]) dfs(fa[x],d+1,dis);
	if(!vis[ch[x][0]] and !dis[ch[x][0]]) dfs(ch[x][0],d+1,dis);
	if(!vis[ch[x][1]] and !dis[ch[x][1]]) dfs(ch[x][1],d+1,dis);
}
void dfs1(int x,int d,int *dis){
	dis[x]=d;
	vec.push_back(x);
	if(!vis[fa[x]] and !dis[fa[x]]) dfs1(fa[x],d+1,dis);
	if(!vis[ch[x][0]] and !dis[ch[x][0]]) dfs1(ch[x][0],d+1,dis);
	if(!vis[ch[x][1]] and !dis[ch[x][1]]) dfs1(ch[x][1],d+1,dis);
}
bool dir(){
	for(auto p:vec){
		dis1[p]=0;
	}
	u=rt;
	dfs(rt,1,dis1);
//	printf("-%d\n",u);
	for(auto p:vec){
		dis1[p]=0;
		dis2[p]=0;
	}
	v=u;
	dfs(v,1,dis1);
//	printf("--%d %d\n",u,v);
	if(u==v) return false;
	vec.clear();
	dfs1(u,1,dis2);
	return true;
}
void solve(){
	scanf("%d",&n);	
	for(int i=1;i<=n;i++) fa[i]=0;
	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;
	while(dir()){
		printf("? %d %d\n",u,v);
		fflush(stdout);
		scanf("%d",&s);
		if(s==1){
			for(auto p:vec){
				if(dis1[p] != dis2[p]) vis[p]=true;
				else rt = p;
			}
		}else if(s==0){
			for(auto p:vec){
				if(dis1[p] <= dis2[p]) vis[p]=true;
				else rt = p;
			}
		}else{
			for(auto p:vec){
				if(dis1[p] >= dis2[p]) vis[p]=true;
				else rt = p;
			}
		}
	}
	printf("! %d\n",u);
	fflush(stdout);
}
int main(){
	int tests;
	scanf("%d",&tests);
	while(tests--){
		solve();
	}
	return 0;
}