#include <bits/stdc++.h>
#define inf 1000000007
#define mod 1000000007
// #define int long long
// #pragma GCC optimize("Ofast","inline","-ffast-math")
// #pragma GCC target("avx,sse2,sse3,sse4,mmx")
using namespace std;
template <typename T> void read(T &x){
	x=0;char ch=getchar();int fh=1;
	while (ch<'0'||ch>'9'){if (ch=='-')fh=-1;ch=getchar();}
	while (ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
	x*=fh;
}
template <typename T> void write(T x) {
	if (x<0) x=-x,putchar('-');
	if (x>9) write(x/10);
	putchar(x%10+'0');
}
template <typename T> void writeln(T x) {
	write(x);
	puts("");
}
int n;
int h[100005],e[200005],ne[200005],idx;
bool cut[200005];
int rt,mn,all;
int siz[200005];
vector<int> pts;
vector<pair<int,int>> edg[100005];
void add(int a,int b)
{
	e[idx]=b,cut[idx]=0,ne[idx]=h[a],h[a]=idx++;
}
void dfs(int x,int fa)
{
	pts.push_back(x);
	siz[x]=1;
	int mx=0;
	for(int i=h[x];~i;i=ne[i])
	{
		int j=e[i];
		if(cut[i]||i==fa) continue;
		dfs(j,i^1);
		edg[x].push_back({siz[j],i});
		siz[x]+=siz[j];
		mx=max(mx,siz[j]);
	}
	if(~fa) edg[x].push_back({all-siz[x],fa});
	mx=max(mx,all-siz[x]);
	if(mn>mx)
		mn=mx,rt=x;
}
int ask(int u,int v)
{
	printf("? %d %d\n",u,v);
	fflush(stdout);
	int res;read(res);
	return res;
}
int solve()
{
	if(edg[rt].size()==0) return rt;
	if(edg[rt].size()==1) return (ask(rt,e[edg[rt][0].second])?e[edg[rt][0].second]:rt);
	if(edg[rt].size()==2)
	{
		int res=ask(e[edg[rt][0].second],e[edg[rt][1].second]);
		if(res==1) return rt;
		if(res) swap(edg[rt][0],edg[rt][1]);
		mn=all=edg[rt][0].first;
		cut[edg[rt][0].second]=cut[edg[rt][0].second^1]=1;
		rt=e[edg[rt][0].second];
		for(int i:pts) edg[i].clear();
		pts.clear();
		dfs(rt,-1);
		return solve();
	}
	sort(edg[rt].begin(),edg[rt].end());
	reverse(edg[rt].begin(),edg[rt].end());
	int res=ask(e[edg[rt][0].second],e[edg[rt][1].second]);
	if(res==0)
	{
		mn=all=edg[rt][0].first;
		cut[edg[rt][0].second]=cut[edg[rt][0].second^1]=1;
		rt=e[edg[rt][0].second];
		for(int i:pts) edg[i].clear();
		pts.clear();
		dfs(rt,-1);
		return solve();
	}
	if(res==1)
	{
		mn=all=edg[rt][2].first+1;
		cut[edg[rt][0].second]=cut[edg[rt][0].second^1]=1;
		cut[edg[rt][1].second]=cut[edg[rt][1].second^1]=1;
		for(int i:pts) edg[i].clear();
		pts.clear();
		dfs(rt,-1);
		return solve();
	}
	mn=all=edg[rt][1].first;
	cut[edg[rt][1].second]=cut[edg[rt][1].second^1]=1;
	rt=e[edg[rt][1].second];
	for(int i:pts) edg[i].clear();
	pts.clear();
	dfs(rt,-1);
	return solve();
}
signed main()
{
	// freopen(".in","r",stdin);
	// freopen(".out","w",stdout);
	int tc;read(tc);
	while(tc--)
	{
		read(n);idx=0;
		for(int i=1;i<=n;++i)
			h[i]=-1;
		for(int i=1;i<=n;++i)
		{
			int x,y;
			read(x);read(y);
			if(x) add(i,x),add(x,i);
			if(y) add(i,y),add(y,i);
		}
		rt=1;mn=all=n;
		for(int i:pts) edg[i].clear();
		pts.clear();
		dfs(rt,-1);
		printf("! %d\n",solve());
		fflush(stdout);
	}
	return 0;
}