#include<bits/stdc++.h>
using namespace std;
const int N=5e4+5;
mt19937 rnd(0x66ccff);
int T,n,s,t,p[N],dp[N],lg[N<<1],mn[N<<1][17],seg[N],m;
vector<int>e[N];
inline int up(int x,int y){
	return dp[x]<dp[y]?x:y;
}
void dfs(int x,int y){
	seg[x]=++m,mn[m][0]=x,dp[x]=dp[y]+1;
	for(auto v:e[x])if(v!=y){
		dfs(v,x);
		mn[++m][0]=x;
	}
}
inline int dis(int x,int y){
	int l=seg[x],r=seg[y];
	if(l>r)swap(l,r);
	int z=lg[r-l+1];
	int p=up(mn[l][z],mn[r-(1<<z)+1][z]);
	return dp[x]+dp[y]-2*dp[p];
}
int E(int x){
	return 1+rnd()%x;
}
bool find(){
	int ct=0;
	p[++ct]=s;
	for(int i=1;i<=n;++i)if(i!=s&&i!=t)p[++ct]=i;
	p[++ct]=t;
	if(n<4)return true;
	shuffle(p+2,p+n,rnd);
	int ans=0,Ans=0;
	for(int i=1;i<n;++i)ans^=dis(p[i],p[i+1]);
	Ans=ans;
	int T=n*20;
	while(T--&&Ans>1){
		int x=1+E(n-2),y=1+E(n-2);
		while(x==y)x=1+E(n-2),y=1+E(n-2);
		int ls=ans;
		ans^=dis(p[x],p[x-1])^dis(p[x],p[x+1]);
		ans^=dis(p[y],p[y-1])^dis(p[y],p[y+1]);
		swap(p[x],p[y]);
		ans^=dis(p[x],p[x-1])^dis(p[x],p[x+1]);
		ans^=dis(p[y],p[y-1])^dis(p[y],p[y+1]);
		Ans=min(Ans,ans);
	}
	return Ans<2;
}
void solve(){
	scanf("%d%d%d",&n,&s,&t);
	m=0;
	for(int i=1;i<=n;++i)e[i].clear();
	for(int i=1,x,y;i<n;++i){
		scanf("%d%d",&x,&y);
		e[x].push_back(y),e[y].push_back(x);
	}
	dfs(1,0);
	for(int j=1;j<=lg[m];++j)
		for(int i=1;i+(1<<j)-1<=m;++i)
			mn[i][j]=up(mn[i][j-1],mn[i+(1<<j-1)][j-1]);
	int G=3;
	while(G--&&!find());
	for(int i=1;i<=n;++i)printf("%d%c",p[i]," \n"[i==n]);
}
int main(){
	for(int i=2;i<N<<1;++i)lg[i]=lg[i>>1]+1;
	scanf("%d",&T);
	while(T--)solve();
	return 0;
}