#include<bits/stdc++.h>
#define ll long long
#define ph push_back
#define rep(i,l,r) for(int i(l),i##end(r);i<=i##end;++i)
#define per(i,r,l) for(int i(r),i##end(l);i>=i##end;--i)
using namespace std;
mt19937 rnd(19937);
const int N=4e5+20; const ll inf=1e18;
int n,de[N],tn,id[N],f[N<<1][17],lg[N<<1],p[N],ans[N]; vector<int> e[N];
void dfs(int u,int fr){
	de[u]=de[fr]+1;
	id[u]=++tn,f[tn][0]=de[u];
	for(int v:e[u]) if(v!=fr){
		dfs(v,u),++tn,f[tn][0]=de[u];
	}
}

inline void swap(int &x,int &y){ x^=y^=x^=y; }

inline int dis(int x,int y){
	x=id[x],y=id[y]; if(x>y) swap(x,y);
	int t=lg[y-x+1];
	return f[x][0]+f[y][0]-min(f[x][t],f[y-(1<<t)+1][t]);
}
void solve(){
	rep(i,1,n) e[i].clear();
	int s,t; 
	scanf("%d%d%d",&n,&s,&t);
	rep(i,2,n) {
		int u,v;
		scanf("%d%d",&u,&v);
		e[u].ph(v),e[v].ph(u);
	}
	tn=0,dfs(1,0);
	rep(i,2,tn) lg[i]=lg[i>>1]+1;
	rep(j,1,16) rep(i,1,tn) {
		if(i+(1<<j-1)<=tn) f[i][j]=min(f[i+(1<<j-1)][j-1],f[i][j-1]);//<=tn!!!
	}
	int cur=1; p[1]=s,p[n]=t;
	rep(i,1,n) if(i!=s&&i!=t) p[++cur]=i; 
	
	int kw,w=0;
	rep(i,2,n) w^=dis(p[i-1],p[i]);
	kw=w; rep(i,1,n) ans[i]=p[i];
	
	if(n<=3) return ;
	
	int T=20*n;
	while(kw>1&&T--){
		//[2,n-1]
		int x=rnd()%(n-2)+2,y=rnd()%(n-3)+2;
		if(y==x) y++;
		w^=dis(p[x-1],p[x])^dis(p[x],p[x+1])^dis(p[y-1],p[y])^dis(p[y],p[y+1]);
		swap(p[x],p[y]);
		w^=dis(p[x-1],p[x])^dis(p[x],p[x+1])^dis(p[y-1],p[y])^dis(p[y],p[y+1]);
		
		if(w<kw){
			kw=w; rep(i,1,n) ans[i]=p[i];
		}
	}
	
}
signed main(){
	int T; scanf("%d",&T);
	while(T--){
		solve();
		rep(i,1,n) printf("%d ",ans[i]); puts("");
//		rep(i,2,n) printf("%d\n",dis(ans[i-1],ans[i])); puts("\n");
	}
	return 0;
}