#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define inf INT_MAX
#define fr(i,l,r) for (i=(l); i<=(r); i++)
#define rfr(i,l,r) for (i=(l); i>=(r); i--)
template<typename T>inline void read(T &n){
    T w=1; n=0; char ch=getchar();
    while (!isdigit(ch) && ch!=EOF){ if (ch=='-') w=-1; ch=getchar(); }
    while (isdigit(ch) && ch!=EOF){ n=(n<<3)+(n<<1)+(ch&15); ch=getchar(); }
    n*=w;
}
template<typename T>inline void write(T x){
    if (x==0){ putchar('0'); return ; }
    T tmp;
    if (x>0) tmp=x;
    else tmp=-x;
    if (x<0) putchar('-');
    char F[105];
    long long cnt=0;
    while (tmp){
        F[++cnt]=tmp%10+48;
        tmp/=10;
    }
    while (cnt) putchar(F[cnt--]);
}
#define Min(x,y) x = min(x,y)
#define Max(x,y) x = max(x,y)
//基础配置=================================================================================
struct Suiji{
    #define R ((ll)rand())
    Suiji(){
        srand((unsigned)time(NULL));
        return ;
    }
    ll rrr(){
        return R*R*R*R+R*R*R+R*R+R;
    }
    ll M(ll l,ll r){
        ll ans,mod;
        ans=rrr();
        mod=r-l+1;
        ans=(ans%mod+mod)%mod;
        return ans+l;
    }
}suiji;
#define M(l,r) (suiji.M(l,r))
const ll N = 50005;
ll n,s,t;
ll d[N],a[N];
struct edge{
    ll x,y;
};
ll cnt=0,head[N]; edge e[N+N];
void addedge(ll x,ll y){
    cnt++;
    e[cnt].x = head[x];
    e[cnt].y = y;
    head[x] = cnt;
}
ll ft[N],dep[N];
void dfs(ll x,ll fa){
    ll i; ll go;
    ft[x] = fa;
    for (i=head[x]; i; i=e[i].x){
        go = e[i].y;
        if (go==fa) continue;
        dep[go] = dep[x]+1;
        dfs(go,x);
    }
}
struct Lca{
    ll lg[N],dep[N];
    ll ft[21][N];
    void init(ll _ft[],ll _dep[]){
        ll i,j;
        lg[1] = 0; fr(i,2,n) lg[i] = lg[i>>1]+1;
        fr(i,1,n) dep[i] = _dep[i], ft[0][i] = _ft[i];
        for (i=1; (1<<i)<=n; i++)
            fr(j,1,n){
                if (ft[i-1][j]) ft[i][j] = ft[i-1][ft[i-1][j]];
                else ft[i][j] = -1;
            }
    }
    ll lca(ll x,ll y){
        if (dep[x]<dep[y]) swap(x,y);
        ll k = dep[x]-dep[y];
        for (ll i=0; (1<<i)<=k; i++)
            if (k&(1<<i)) x = ft[i][x];
        if (x==y) return x;
        for (ll i=lg[dep[x]]; i>=0; i--)
            if (ft[i][x]!=ft[i][y])
                x = ft[i][x], y = ft[i][y];
        return ft[0][x];
    }
    ll dis(ll x,ll y){
        ll l = lca(x,y);
        return dep[x]+dep[y]-2*dep[l];
    }
}lc;
bool check(){
    ll mx = 0;
    for (ll i=1; i<=n; i++) Max(mx,d[i]);
    return mx==n-1;
}
struct Baoli{
    ll ans = inf;
    bool vis[20];
    ll a[20],b[20];
    void dfs(ll x,ll v){
        ll i;
        if (ans<=1) return ;
        if (x==n){
            v ^= lc.dis(a[n-1],t);
            if (v<ans){
                fr(i,1,n) b[i] = a[i];
                ans = v;
            }
            return ;
        }
        fr(i,1,n){
            if (vis[i]) continue;
            a[x] = i; vis[i] = true;
            dfs(x+1,v^lc.dis(i,a[x-1]));
            vis[i] = false;
        }
    }
    void main(){
        memset(vis,false,sizeof(vis));
        vis[s] = vis[t] = true;
        a[1] = s; a[n] = t;
        ans = inf;
        dfs(2,0);
        ll i;
        // printf("ans = %lld\n",ans);
        fr(i,1,n) printf("%lld ",b[i]); putchar('\n');
        return ;
    }
}baoli;
ll calc(){
    ll i;
    ll ans = 0;
    fr(i,2,n)
        ans ^= lc.dis(a[i-1],a[i]);
    return ans;
}
void work(){
    ll i,j;
    read(n); read(s); read(t);
    cnt = 0; fr(i,1,n) head[i] = d[i] = 0;
    fr(i,2,n){
        ll x,y;
        read(x); read(y);
        addedge(x,y);
        addedge(y,x);
        d[x]++; d[y]++;
    }
    dep[1] = 1; dfs(1,-1);
    lc.init(ft,dep);
    // fr(i,1,n)
    //     fr(j,1,n)
    //         printf("dis %lld %lld = %lld\n",i,j,lc.dis(i,j));
    if (check()){
        printf("%lld ",s);
        fr(i,1,n)
            if (i!=s && i!=t) printf("%lld ",i);
        printf("%lld\n",t);
        return ;
    }
    if (n<=9){ baoli.main(); return ; }
    ll pos = 1;
    a[1] = s; a[n] = t;
    fr(i,1,n)
        if (i!=s && i!=t) a[++pos] = i;
    fr(i,1,5*n) swap(a[M(2,n-1)],a[M(2,n-1)]);
    // fr(i,1,n) printf("a[%lld] = %lld\n",i,a[i]);
    ll ans = calc();
    while (ans>1){
        ll x = M(2,n-2);
        ans = ans^lc.dis(a[x-1],a[x]) ^ lc.dis(a[x+1],a[x+2]);
        swap(a[x],a[x+1]);
        ans = ans^lc.dis(a[x-1],a[x]) ^ lc.dis(a[x+1],a[x+2]);
    }
    fr(i,1,n) printf("%lld ",a[i]); putchar('\n');
}
int main(){
	// freopen("a.in","r",stdin);
//	freopen(".out","w",stdout);
    ll qt;
    read(qt);
    while (qt--) work();
    return 0;
}
//g++ a.cpp -o a -Wall -Wl,--stack=512000000 -std=c++11 -O2