#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
using ll=long long;
using pii=pair<int,int>;
using vi=vector<int>;
using vl=vector<ll>;
#define pb push_back
#define all(a) begin(a),end(a)

const int N=300010,MOD=1e9+7;
const char en='\n';
const ll LLINF=1ll<<60;

const bool DEB=0;

int t,n,ss[N],par[N],ppar[N],de[N],s;
vi ch[N],ch1[N],ord;

int dis(int a,int b)
{
	int an=0;
	while (a!=b)
	{
		if (de[a]<de[b]) b=ppar[b];
		else a=ppar[a];
		++an; 
	}
	return an;
}

int ask(int a,int b)
{
	cout<<"? "<<a<<' '<<b<<endl;
	if (DEB)
	{
		if (dis(a,s)<dis(b,s)) return 0;
		if (dis(a,s)==dis(b,s)) return 1;
		if (dis(a,s)>dis(b,s)) return 2;
		assert(0);
	}
	else
	{
		int x;
		cin>>x;
		return x;
	}
}

void dfs(int i,int p=-1)
{
	ss[i]=1;
	ord.pb(i);
	par[i]=p;
	for (auto x: ch[i]) if (x!=p)
	{
		dfs(x,i);
		ss[i]+=ss[x];
	}
}

void dfs1(int i,int p=-1)
{
	ppar[i]=p;
	for (auto x: ch[i]) if (x!=p)
	{
		de[x]=de[i]+1;
		dfs1(x,i);
	}
}

void rem(int a,int b)
{
	ch[a].erase(find(all(ch[a]),b));
	ch[b].erase(find(all(ch[b]),a));
}

int solve(int r)
{
	ord.clear();
	dfs(r);
	if (ss[r]==1)
	{
		cout<<"! "<<r<<endl;
		return -1;
	}
	if (ss[r]==2)
	{
		int b=ch[r][0];
		int re=ask(r,b);
		rem(r,b);
		if (re==0) return r;
		if (re==2) return b;
		assert(0);
	}
	int cn=ss[r],cen=-1;
	for (auto x: ord)
	{
		if (cn-ss[x]>cn/2) continue;
		bool ok=1;
		for (auto y: ch[x]) if (y!=par[x] && ss[y]>cn/2) ok=0;
		if (ok) cen=x;
	}
	assert(cen!=-1);
	if (ch[cen].size()==2)
	{
		int a=ch[cen][0],b=ch[cen][1];
		rem(cen,a);
		rem(cen,b);
		int re=ask(a,b);
		if (re==0) return a;
		if (re==2) return b;
		if (re==1) return cen;
	}
	int mal=-1;
	for (auto x: ch[cen]) if (ss[x]<cn/2) mal=x;
	assert(mal!=-1);
	int a=-1,b=-1;
	for (auto x: ch[cen]) if (x!=mal)
	{
		if (a==-1) a=x;
		else b=x;
	}
	rem(cen,a);
	rem(cen,b);
	//rem(cen,mal);
	int re=ask(a,b);
	if (re==0) return a;
	if (re==1) return mal;
	if (re==2) return b;
}

int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin>>t;
	while (t--)
	{
		cin>>n;
		for (int i=1;i<=n;++i) ch[i].clear();
		for (int i=1;i<=n;++i)
		{
			int x,y;
			cin>>x>>y;
			if (x) ch[x].pb(i),ch[i].pb(x);
			if (y) ch[y].pb(i),ch[i].pb(y);
		}
		dfs1(1);
		if (DEB)
		{
			for (int i=1;i<=n;++i) ch1[i]=ch[i];
			for (s=1;s<=n;++s)
			{
				for (int i=1;i<=n;++i) ch[i]=ch1[i];
				int cu=1;
				while (cu!=-1) cu=solve(cu);
			}
		}
		else
		{
			int cu=1;
			while (cu!=-1) cu=solve(cu);
		}
	}
}