#include<cstdio>
#include<cstring>
#include<algorithm>
#define ft fflush(stdout)
using namespace std;
int n,hed[1000001],net[2000001],ver[2000001],tot;
void add(int x,int y){
	ver[++tot]=y;
	net[tot]=hed[x];
	hed[x]=tot;
}
bool cut[1000001];
int sz[1000001],son[1000001],deg[1000001];
int qr(int x,int y){
	ft;
	printf("? %d %d\n",x,y);
	ft;
	int res;
	scanf("%d",&res);
	ft;
	return res;
}
void dfs0(int x,int fr){
	sz[x]=1;son[x]=0;
	int i;
	for(i=hed[x];i;i=net[i]){
		int y=ver[i];
		if(y==fr||cut[y])continue;
		dfs0(y,x);
		sz[x]+=sz[y];
		if(sz[y]>=sz[son[x]])son[x]=y;
	}
}
int findh(int x,int ps){
	while(son[x]&&sz[son[x]]>ps/2)x=son[x];
	return x;
}
void dfs(int x){
	int i;
	dfs0(x,0);
	cut[x]=1;
	for(i=hed[x];i;i=net[i]){
		int y=ver[i];
		if(cut[y])deg[x]--;
	}
	if(!deg[x]){
		ft;
		printf("! %d\n",x);
		ft;
		return;
	}
	int f1=0,f2=0,f3=0;
	for(i=hed[x];i;i=net[i]){
		int y=ver[i];
		if(cut[y])continue;
		if(!f1)f1=y;
		else if(!f2)f2=y;
		else f3=y;
	}
	if(deg[x]==1){
		ft;
		int res=qr(x,f1);
		if(!res)printf("! %d\n",x);
		else printf("! %d\n",f1);
		ft;
		return;
	}
	if(deg[x]==2){
		ft;
		int res=qr(f1,f2);
		if(res==0)dfs(findh(f1,sz[f1]));
		else if(res==1)printf("! %d\n",x);
		else dfs(findh(f2,sz[f2]));
		ft;
		return;
	}
	int mn=min(sz[f1],min(sz[f2],sz[f3]));
	if(sz[f1]==mn)f1^=f3^=f1^=f3;
	else if(sz[f2]==mn)f2^=f3^=f3^=f3;
	int res=qr(f1,f2);
	if(res==1){
		cut[x]=0;
		cut[f1]=cut[f2]=1;
		dfs0(x,0);
		dfs(findh(x,sz[x]));
		return;
	}
	if(res==0)dfs(findh(f1,sz[f1]));
	else dfs(findh(f2,sz[f2]));
}
void solve(){
	int i,j;
	scanf("%d",&n);
	tot=0;
	for(i=1;i<=n;i++)cut[i]=deg[i]=hed[i]=0;
	for(i=1;i<=n;i++){
		int x,y;
		scanf("%d%d",&x,&y);
		if(x){
			add(i,x);add(x,i);
			deg[x]++;deg[i]++;
		}
		if(y){
			add(i,y);add(y,i);
			deg[y]++;deg[i]++;
		}
	}
	ft;
	dfs0(1,0);
	dfs(findh(1,n));
}
int main(){
	int t;
	scanf("%d",&t);
	while(t--)solve();
}