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

//#define int long long
#define ls p<<1
#define rs p<<1|1
#define msp(_array) memset(_array,0x3f,sizeof _array)
#define ms0(_array) memset(_array,0,sizeof _array)
#define msn(_array) memset(_array,-1,sizeof _array)
#define mc(_tar,_array) memcpy(_tar,_array,sizeof _tar)
#define pii pair<int,int>
#define endl '\n'

bool bg_memory;
const int mod=1e9+7;
const int inf=2147483647;
const int bs=233;
const double eps=1e-6;
const int N=1e5+7,M=1e5+7;
inline void cmax(int &a,int b){a=a<b?b:a;}
inline void cmin(int &a,int b){a=a>b?b:a;}
inline int qp(int a,int b){int res=1;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;}

int n,s,t;
int u,v;
vector<int> e[N];
int dep[N];
int fa[N][17];
int ans[N];
void dfs(int x,int p){
    fa[x][0]=p;
    dep[x]=dep[p]+1;
    for(int i=1;i<=16;i++) fa[x][i]=fa[fa[x][i-1]][i-1];
    for(int i:e[x]){
        if(i==p) continue;
        dfs(i,x);
    }
}
int lca(int u,int v){
    if(dep[u]>dep[v]) swap(u,v);
    for(int i=16;i>=0;i--) if(dep[fa[v][i]]>=dep[u]) v=fa[v][i];
    if(u==v) return u;
    for(int i=16;i>=0;i--) if(fa[v][i]!=fa[u][i]) u=fa[u][i],v=fa[v][i];
    return fa[u][0];
}

mt19937 rnd(time(0));
int Case=1;
void Main(){
    
    cin>>n>>s>>t;
    for(int i=1;i<=n;i++) e[i].clear();
    for(int i=1;i<n;i++){
        cin>>u>>v;
        e[u].push_back(v);
        e[v].push_back(u);
    }
    dfs(1,0);
    for(int i=1;i<=n;i++){
        if(e[i].size()==n-1){
            cout<<s<<" ";
            for(int j=1;j<=n;j++){
                if(s==j||t==j) continue;
                cout<<j<<" ";
            }
            cout<<t<<endl;
            return;
        }
    }
    if(n==4){
        int cnt=0;
        for(int i=1;i<=4;i++) cnt+=(e[i].size()==2&&(i==s||i==t));
        if(cnt==2){
            cout<<s<<" ";
            for(int i=1;i<=4;i++){
                if(i!=s&&i!=t) cout<<i<<" ";
            }
            cout<<t<<endl;
        }
    }
    ans[1]=s;
    int tot=1;
    for(int i=1;i<=n;i++) if(i!=s&&i!=t) ans[++tot]=i;
    ans[n]=t;
    shuffle(ans+2,ans+n,rnd);
    int res=0;
    for(int i=2;i<=n;i++){
        res^=(dep[ans[i]]+dep[ans[i-1]]-2*dep[lca(ans[i],ans[i-1])]);
    }
    if(n<=9){
        sort(ans+2,ans+n);
        do{
            res=0;
            for(int i=2;i<=n;i++){
                res^=(dep[ans[i]]+dep[ans[i-1]]-2*dep[lca(ans[i],ans[i-1])]);
            }
            if(res<=1){
                for(int i=1;i<=n;i++) cout<<ans[i]<<" ";
                cout<<endl;
                return;
            }
        }while(next_permutation(ans+2,ans+n));
    }else{
        while(1){
            int lr=rnd()%(n-3)+3;
            int rr=rnd()%(lr-2)+2;
            res^=(dep[ans[lr]]+dep[ans[lr-1]]-2*dep[lca(ans[lr],ans[lr-1])]);
            res^=(dep[ans[lr]]+dep[ans[lr+1]]-2*dep[lca(ans[lr],ans[lr+1])]);
            res^=(dep[ans[rr]]+dep[ans[rr-1]]-2*dep[lca(ans[rr],ans[rr-1])]);
            res^=(dep[ans[rr]]+dep[ans[rr+1]]-2*dep[lca(ans[rr],ans[rr+1])]);
            swap(ans[lr],ans[rr]);
            res^=(dep[ans[lr]]+dep[ans[lr-1]]-2*dep[lca(ans[lr],ans[lr-1])]);
            res^=(dep[ans[lr]]+dep[ans[lr+1]]-2*dep[lca(ans[lr],ans[lr+1])]);
            res^=(dep[ans[rr]]+dep[ans[rr-1]]-2*dep[lca(ans[rr],ans[rr-1])]);
            res^=(dep[ans[rr]]+dep[ans[rr+1]]-2*dep[lca(ans[rr],ans[rr+1])]);
            if(res<=1){
                for(int i=1;i<=n;i++) cout<<ans[i]<<" ";
                cout<<endl;
                return;
            }
        }    
    }
    
    
    return;
}
string RdFile="";
bool en_memory;

signed main(){
    auto bg_clock=chrono::high_resolution_clock::now();
// #ifdef ONLINE_JUDGE
//     freopen((RdFile+".in").c_str(),"r",stdin);
//     freopen((RdFile+".out").c_str(),"w",stdout);    
// #endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin>>Case;
    while(Case--) Main();
    auto en_clock=chrono::high_resolution_clock::now();
    auto duration_clock=chrono::duration_cast<chrono::microseconds>(en_clock-bg_clock);
#ifndef ONLINE_JUDGE
    cerr<<endl<<"code_time_used: "<<duration_clock.count()*0.001<<"ms"<<endl;
    cerr<<"code_memory_used: "<<(&en_memory-&bg_memory)/1024.0/1024<<"MB"<<endl;
#endif
    return 0;
}