#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const int INF=1000000000;
const int maxn=100000;

mt19937 rng((unsigned long long)(new char));

int n,s,t;
vector<int> g[maxn+50];

int len=0;
int st[21][maxn+50];
int dep[maxn+50];
int id[maxn+50];
int lg[maxn+50];

void dfs(int u,int fa){
	st[0][++len]=u;
	id[u]=len;
	for (auto v:g[u]) if (v!=fa){
		dep[v]=dep[u]+1;
		dfs(v,u);
		st[0][++len]=u;
	}
}
void st_prepare(){
	lg[0]=-1;
	for (int i=1;i<=len;i++) lg[i]=lg[i>>1]+1;
	for (int L=1;L<=20;L++){
		for (int i=1;i+(1<<L)-1<=len;i++){
			int t1=st[L-1][i];
			int t2=st[L-1][i+(1<<(L-1))];
			if (dep[t1]<dep[t2]) st[L][i]=t1;
			else st[L][i]=t2;
		}
	}
}
int lca(int u,int v){
	u=id[u];
	v=id[v];
	if (u>v) swap(u,v);
	int L=lg[v-u+1];
	int t1=st[L][u];
	int t2=st[L][v-(1<<L)+1];
	if (dep[t1]<dep[t2]) return t1;
	else return t2;
}
int dis(int u,int v){
	return dep[u]+dep[v]-dep[lca(u,v)]*2;	
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	int Tcase=1;
	cin >> Tcase;
	for (;Tcase--;){
		cin >> n >> s >> t;
		for (int i=1;i<n;i++){
			int x,y;
			cin >> x >> y;
			g[x].push_back(y);
			g[y].push_back(x);
		}
		if (n<=7){
			vector<vector<int>> f(n+1,vector<int>(n+1));
			for (int i=1;i<=n;i++){
				for (int j=1;j<=n;j++){
					if (i==j) f[i][j]=0;
					else f[i][j]=INF;
				}
			}
			for (int u=1;u<=n;u++){
				for (auto v:g[u]) f[u][v]=1;
			}
			for (int k=1;k<=n;k++)
				for (int i=1;i<=n;i++) if (k!=i)
					for (int j=1;j<=n;j++) if (k!=j && i!=j){
						f[i][j]=min(f[i][j],f[i][k]+f[k][j]);	
					}
			vector<int> perm;
			perm.push_back(s);
			for (int i=1;i<=n;i++){
				if (i!=s && i!=t){
					perm.push_back(i);
				}	
			}
			perm.push_back(t);
			pair<int,vector<int>> ans;
			ans.first=INF; 
			do{
				int sum=0;
				for (int i=1;i<n;i++) sum=sum^f[perm[i-1]][perm[i]];
				if (sum<ans.first){
					ans.first=sum;
					ans.second=perm;
				}
			}while (next_permutation(perm.begin()+1,perm.end()-1));
			
			for (auto e:ans.second) cout << e << " ";
			cout << "\n";
		}
		else{
			dfs(1,0);
			st_prepare();
			vector<int> perm;
			perm.push_back(s);
			for (int i=1;i<=n;i++){
				if (i!=s && i!=t){
					perm.push_back(i);
				}
			}
			perm.push_back(t);
			pair<int,vector<int>> ans;
			ans.first=INF;
			
			vector<int> pos(n+n+5);
			int lim=50;
			if (n>=30) lim=35;
			for (int cc=1;cc<=lim;cc++){
				shuffle(perm.begin()+1,perm.end()-1,rng);
				for (int i=1;i+2<n;i+=3){
					int pre=dis(perm[i-1],perm[i])^dis(perm[i+1],perm[i+2]);
					int now=dis(perm[i-1],perm[i+1])^dis(perm[i],perm[i+2]);
					pos[pre^now]=i;
				}
				int sum=0;
				for (int i=1;i<n;i++) sum=sum^dis(perm[i-1],perm[i]);
				for (int i=sum;i>=0;i--){
					if (pos[i] && (sum^i)<sum){
						sum^=i;
						swap(perm[pos[i]],perm[pos[i]+1]);
					}
				}
				if (sum<ans.first){
					ans.first=sum;
					ans.second=perm;	
				}
				for (int i=0;i<n+n+5;i++) pos[i]=0;
			}

			for (auto e:ans.second) cout << e << " ";
			cout << "\n";
		}
		
		len=0;
		for (int i=1;i<=n;i++){
			g[i].clear();	
		}
	}
	return 0;
}