#include<bits/stdc++.h>
using namespace std;bool Mbe;
inline int Ask(int x,int y){printf("? %d %d\n",x,y);scanf("%d",&x);return x;}
inline void Rep(int x){printf("! %d\n",x);}
namespace MAOJUN{

const int N=1e5+5;
int n;
const int E=N<<1;
int tot=0,hd[N],to[E],nxt[E];
inline void Add(int u,int v){to[++tot]=v;nxt[tot]=hd[u];hd[u]=tot;}

int al,mn,wc,sz[N];bool vs[N];
void gwc(int u,int f){
	int mx=0;sz[u]=1;
	for(int i=hd[u];i;i=nxt[i])if(int v=to[i];v!=f&&!vs[v]){
		gwc(v,u);sz[u]+=sz[v];mx=max(mx,sz[v]);
	}
	mx=max(mx,al-sz[u]);if(mx<mn){mn=mx;wc=u;}
}
int dvd(int u){
	vector<int>sn;vs[u]=1;gwc(u,0);
	for(int i=hd[u];i;i=nxt[i])if(int v=to[i];!vs[v])sn.emplace_back(v);
	if(sn.size()==0)return u;
	else if(sn.size()==1)return Ask(u,sn[0])?sn[0]:u;
	else if(sn.size()==2){
		int x=Ask(sn[0],sn[1]);
		if(x==1)return u;
		int v=x?sn[1]:sn[0];
		al=mn=sz[v];gwc(v,u);
		return dvd(wc);
	}
	int x=Ask(sn[0],sn[1]);
	if(x==1){
		vs[u]=0;vs[sn[0]]=vs[sn[1]]=1;
		al=mn=sz[sn[2]]+1;gwc(u,0);return dvd(wc);
	}
	int v=x?sn[1]:sn[0];
	al=mn=sz[v];gwc(v,u);
	return dvd(wc);
}
inline void slv(){
	scanf("%d",&n);
	tot=0;for(int i=1;i<=n;i++)hd[i]=vs[i]=0;
	for(int i=1,u,v;i<=n;i++){
		scanf("%d%d",&u,&v);
		if(u){Add(i,u);Add(u,i);}
		if(v){Add(i,v);Add(v,i);}
	}
	al=mn=n;gwc(1,0);Rep(dvd(wc));
}
inline void main(){
	int T;scanf("%d",&T);while(T--)slv();
}

}bool Med;int main(){
	MAOJUN::main();
#ifdef LOCAL
	fprintf(stderr,"%lfs\n",clock()/1000.);
	fprintf(stderr,"%lfMB\n",(&Mbe-&Med)/1024./1024);
#endif
	return 0;
}