#include<bits/stdc++.h>
using namespace std;
mt19937 fxk(time(0));
inline int rnd(int x){return fxk()%x+1;}
inline int qread()
{
	int a=0,f=1;char ch=getchar();
	while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
	while(isdigit(ch)){(a*=10)+=(ch^48);ch=getchar();}
	return a*f;
}
int T,n,s,t,ans,nans,dfn[50010],tot,fa[50010],st[16][50010],dep[50010],p[50010];
int bans,a[10],vis[10];
vector<int>e[50010];
inline int cmp(int x,int y){return dfn[x]<dfn[y]?x:y;}
inline void dfs(int rt,int da)
{
	dep[rt]=dep[da]+1;fa[rt]=da;
	dfn[rt]=++tot;st[0][tot]=da;
	for(int i:e[rt])
	{
		if(i==da)continue;
		dfs(i,rt);
	}
	return ;
}
inline int LCA(int x,int y)
{
	if(x==y)return x;
	if((x=dfn[x])>(y=dfn[y]))swap(x,y);
	int s=31-__builtin_clz(y-x++);
	return cmp(st[s][x],st[s][y-(1<<s)+1]);
}
inline int dis(int x,int y){return dep[x]+dep[y]-(dep[LCA(x,y)]<<1);}
inline bool check()
{
	for(int i=1;i<=n;++i)if((int)e[i].size()==n-1)return 1;
	return 0;
}
inline void dfss(int h)
{
	if(h==1)a[h]=s,dfss(h+1);
	else if(h==n)a[h]=t,bans^=dis(a[h],a[h-1]),dfss(h+1),bans^=dis(a[h],a[h-1]);
	else if(h==n+1)
	{
		if(bans<ans)
		{
			for(int i=1;i<=n;++i)p[i]=a[i];
			ans=bans;
		}
		return ;
	} 
	else 
	{
		for(int i=1;i<=n;++i)if(!vis[i]&&dis(i,a[h-1])<=4)
		{
			bans^=dis(i,a[h-1]);
			a[h]=i;vis[i]=1;
			dfss(h+1);
			bans^=dis(i,a[h-1]);
			vis[i]=0;
		}
	}
	return ;
}
int main()
{
	T=qread();
	while(T--)
	{
		for(int i=1;i<=n;++i)vector<int>().swap(e[i]);
		n=qread(),s=qread(),t=qread();tot=0;ans=5;
		for(int i=1,u,v;i<n;++i)
		{
			u=qread(),v=qread();
			e[u].emplace_back(v);
			e[v].emplace_back(u);
		}
		dfs(1,0);
		for(int i=1;i<=15;++i)for(int j=1;j+(1<<i)-1<=n;++j)st[i][j]=cmp(st[i-1][j],st[i-1][j+(1<<(i-1))]);
		if(check())
		{
			printf("%d ",s);
			for(int i=1;i<=n;++i)if(i^s&&i^t)printf("%d ",i);
			printf("%d\n",t);
			continue;
		}
		else if(n<=9)
		{
			vis[s]=vis[t]=1;bans=0;
			dfss(1);
			vis[s]=vis[t]=0;
			for(int i=1;i<=n;++i)printf("%d ",p[i]);puts("");
		}
		else
		{
			p[1]=s,p[n]=t;nans=0;
			for(int i=1,lp=2;i<=n;++i)if(i^s&&i^t)p[lp++]=i;
			for(int i=2;i<=n;++i)nans^=dis(p[i-1],p[i]);ans=nans;
			while(ans>1)
			{
				int A=rnd(n-2)+1,B=rnd(n-2)+1;
				while(A==B)B=rnd(n-2)+1;
				nans^=dis(p[A],p[A-1])^dis(p[A],p[A+1]);
				nans^=dis(p[B],p[B-1])^dis(p[B],p[B+1]);
				swap(p[A],p[B]);
				nans^=dis(p[A],p[A-1])^dis(p[A],p[A+1]);
				nans^=dis(p[B],p[B-1])^dis(p[B],p[B+1]);
				ans=min(ans,nans);
			}
			for(int i=1;i<=n;++i)printf("%d ",p[i]);puts("");
		}
	}
	return 0;
}