#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<random>
#include<cassert>
#define rep(i, a, b) for(int i = (a); i <= (b); i++)
#define per(i, a, b) for(int i = (a); i >= (b); i--)
using namespace std;
typedef long long ll;
mt19937 rnd(37);
const int N = 500010;
int n, s, t, deg[N], dep[N], sz[N], fa[N], top[N], son[N];
vector<int> e[N];
void dfs1(int x, int F){
    dep[x] = dep[F] + 1, fa[x] = F; sz[x] = 1;
    for(int &y : e[x]) if(y ^ F){
        dfs1(y, x);
        if(sz[y] > sz[son[x]]) son[x] = y;
    }
}
void dfs2(int x, int tp){
    top[x] = tp;
    for(int &y : e[x]) if(y ^ fa[x])
        dfs2(y, y==son[x] ? tp : y);
}
int lca(int x, int y){
    while(1){
        if(top[x] == top[y]) return dep[x]<dep[y] ? x : y;
        if(dep[top[x]] < dep[top[y]]) swap(x, y);
        x = fa[top[x]];
    }
}
int dis(int x, int y) {return dep[x]+dep[y]-2*dep[lca(x, y)];}

int a[N];
int calc(){
    int ret = 0;
    rep(i, 2, n) ret ^= dis(a[i-1], a[i]);
    return ret;    
}

void solve1(){
    int ans = N;
    sort(a+2, a+n);
    do ans = min(ans, calc()); while(next_permutation(a+2, a+n));
    sort(a+2, a+n);
    do{
        if(ans == calc()){
            rep(i, 1, n) printf("%d ", a[i]);
            putchar('\n'); return;
        }
    } while(next_permutation(a+2, a+n));
}

void solve2(){
    int t = calc();
    while(t > 1){
        int x = rnd() % (n-2)+2, y = rnd() % (n-2)+2;
        t = t ^ dis(a[x-1], a[x]) ^ dis(a[x], a[x+1]) ^ dis(a[y-1], a[y]) ^ dis(a[y], a[y+1]);
        swap(a[x], a[y]);
        t = t ^ dis(a[x-1], a[x]) ^ dis(a[x], a[x+1]) ^ dis(a[y-1], a[y]) ^ dis(a[y], a[y+1]);
    }
    rep(i, 1, n) printf("%d ", a[i]);
    putchar('\n');
}

void solve(){
    scanf("%d%d%d", &n, &s, &t);
    rep(i, 1, n) deg[i] = 0, son[i] = 0, e[i].clear();
    rep(i, 1, n-1){
        int x, y; scanf("%d%d", &x, &y);
        e[x].push_back(y), e[y].push_back(x);
        deg[x]++, deg[y]++;
    }
    rep(i, 1, n) a[i] = i;
    rep(i, 1, n) if(a[i] == s) {swap(a[1], a[i]); break;}
    rep(i, 1, n) if(a[i] == t) {swap(a[n], a[i]); break;}
    rep(i, 1, n) if(deg[i] == n-1){
        rep(j, 1, n) printf("%d ", a[j]);
        putchar('\n'); return;
    }
    dfs1(1, 0); dfs2(1, 1);
    if(n <= 9) solve1();
    else solve2();
}

int main(){
    int T; scanf("%d", &T); while(T--) solve();
    return 0;
}