#include<cstdio>
#include<iostream>
#include<vector>
#include<algorithm>
#define RI register int
#define CI const int&
using namespace std;
const int N=100005;
int t,n,x,y,sz[N],mx[N],vis[N],rt,ots; vector <int> v[N];
inline int ask(CI u,CI v)
{
	printf("? %d %d\n",u,v); fflush(stdout);
	int res; scanf("%d",&res); return res;
}
inline void answer(CI x)
{
	printf("! %d\n",x); fflush(stdout);
}
inline void getrt(CI now=1,CI fa=0)
{
	sz[now]=1; mx[now]=0;
	for (auto to:v[now]) if (to!=fa&&!vis[to])
	{
		getrt(to,now); sz[now]+=sz[to];
		mx[now]=max(mx[now],sz[to]);
	}
	mx[now]=max(mx[now],ots-sz[now]);
	if (mx[now]<mx[rt]) rt=now;
}
inline void solve(int now)
{
	vector <int> son;
	for (auto to:v[now]) if (!vis[to]) son.push_back(to);
	if (son.empty()) return answer(now);
	if (son.size()==1)
	{
		int res=ask(now,son.back());
		if (res==0) answer(now); else answer(son.back());
		return;
	}
	if (son.size()==2)
	{
		int res=ask(son[0],son[1]);
		if (res==0)
		{
			vis[now]=1; mx[rt=0]=ots=sz[son[0]];
			getrt(son[0],now); getrt(rt); solve(rt);
		} else
		if (res==2)
		{
			vis[now]=1; mx[rt=0]=ots=sz[son[1]];
			getrt(son[1],now); getrt(rt); solve(rt);
		} else answer(now);
		return;
	}
	auto cmp=[&](CI x,CI y)
	{
		return sz[x]>sz[y];
	};
	sort(son.begin(),son.end(),cmp);
	int res=ask(son[0],son[1]);
	if (res==0)
	{
		vis[now]=1; mx[rt=0]=ots=sz[son[0]];
		getrt(son[0],now); getrt(rt); solve(rt);
	} else
	if (res==2)
	{
		vis[now]=1; mx[rt=0]=ots=sz[son[1]];
		getrt(son[1],now); getrt(rt); solve(rt);
	} else
	{
		vis[son[0]]=vis[son[1]]=1; getrt(now);
		mx[rt=0]=ots=sz[now];
		getrt(now); getrt(rt); solve(rt);
	}
	return;
}
int main()
{
	for (scanf("%d",&t);t;--t)
	{
		scanf("%d",&n);
		for (RI i=1;i<=n;++i) vis[i]=0,v[i].clear();
		for (RI i=1;i<=n;++i)
		{
			scanf("%d%d",&x,&y);
			if (x!=0) v[i].push_back(x),v[x].push_back(i);
			if (y!=0) v[i].push_back(y),v[y].push_back(i);
		}
		mx[rt=0]=ots=n; getrt(); solve(rt);
	}
}