#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int MAXN=2e6+7;
int t,n;
int cnt=1,head[MAXN],to[MAXN],nxt[MAXN];
int siz[MAXN],now_sum=0,maxl[MAXN];
int tot=0,id[MAXN],fa[MAXN];
bool vis[MAXN];
bool edge[MAXN];
void add(int x,int y)
{
	to[++cnt]=y;
	nxt[cnt]=head[x];
	head[x]=cnt;
	return;
}
void dfs(int x)
{
	id[++tot]=x;
	vis[x]=1;siz[x]=1;maxl[x]=0;
	for(int i=head[x];i;i=nxt[i])
	{
		int y=to[i];
		if(vis[y]||edge[i]) continue;
		fa[y]=x;
		dfs(y);
		siz[x]+=siz[y];
		maxl[x]=max(maxl[x],siz[y]);
	}
	maxl[x]=max(maxl[x],now_sum-siz[x]);
	return;
}
struct hhh
{
	int s,id;
}c[MAXN];
bool cmp(hhh x,hhh y)
{
	return x.s>y.s;
}
int main()
{
//	ios::sync_with_stdio(false);
//	cin.tie(0);cout.tie(0);
	

	cin>>t;
	while(t--)
	{
		cin>>n;
		for(int i=1;i<=n;i++)
		{
			int u=i,v;
			cin>>v;
			if(v) add(u,v),add(v,u);
			cin>>v;
			if(v) add(u,v),add(v,u);
		}
		now_sum=n;
		int rot=1;
		while(1)
		{
			tot=0;
			dfs(rot);
			int minl=1e9,min_id;
			if(tot==1)
			{
				cout<<"! "<<id[1]<<endl;
				break;
			}
			for(int i=1;i<=tot;i++)
			{
				int x=id[i];
				if(maxl[x]<minl)
				{
					minl=maxl[x];
					min_id=x;
				}
			}
			int numk=0;
			for(int i=head[min_id];i;i=nxt[i])
			{
				int y=to[i];
				if(fa[min_id]==y||edge[i]) continue;
				c[++numk]={siz[y],y};
			}
			if(min_id!=rot)
			{
				c[++numk]={now_sum-siz[min_id],fa[min_id]};
			}
			sort(c+1,c+1+numk,cmp);
			if(numk>1)
			{
				cout<<"? "<<c[1].id<<" "<<c[2].id<<endl;
				int sss;
				cin>>sss;
				if(sss==0)
				{
					int x=c[1].id;
					for(int i=head[x];i;i=nxt[i])
					{
						int y=to[i];
						if(y==min_id)
						{
							edge[i]=edge[i^1]=1;
							break;
						}
					}
					rot=x;
					now_sum=siz[rot];
				}
				else if(sss==2)
				{
					int x=c[2].id;
					for(int i=head[x];i;i=nxt[i])
					{
						int y=to[i];
						if(y==min_id)
						{
							edge[i]=edge[i^1]=1;
							break;
						}
					}
					rot=x;
					now_sum=siz[rot];
				}
				else
				{
					cout<<"! "<<min_id<<endl;
					break;
				}
			}
			else
			{
				cout<<"? "<<min_id<<" "<<c[1].id<<endl;
				int sss;
				cin>>sss;
				if(sss==0) cout<<"! "<<min_id<<endl;
				else cout<<"! "<<c[1].id<<endl;
				break;
			}
			
		}
		for(int i=0;i<=n;i++) 
		{
			head[i]=vis[i]=siz[i]=0;
		}
		for(int i=0;i<=cnt;i++) nxt[i]=to[i]=edge[i]=0;
		cnt=1;
	}
	return 0;
}
/*
1
10 2
2 5 2 1 10 3 2 9 9 6
17 9
*/