// I
#include <bits/stdc++.h>
#define ll long long
#define rep(i, s, t) for(int i=s; i<=t; ++i)
#define debug(x) cerr<<#x<<":"<<x<<endl;
const int N=500010; ll inf=4e18;
using namespace std;
mt19937 rrnd(time(0));
int rnd(int l, int r) {return rrnd()%(r-l+1)+l;}

int T, n, s, t; vector<int> g[N];
int d[N], f[N][20];
void dfs(int u, int fa)
{
    d[u]=d[fa]+1; f[u][0]=fa;
    rep(i, 1, 16) f[u][i]=f[f[u][i-1]][i-1];
    for(int v:g[u]) if(v!=fa) dfs(v, u);
}
int lca(int u, int v)
{
    if(d[u]<d[v]) swap(u, v);
    for(int i=16; i>=0; i--) if(d[f[u][i]]>=d[v]) u=f[u][i];
    if(u==v) return u;
    for(int i=16; i>=0; i--) if(f[u][i]!=f[v][i]) u=f[u][i], v=f[v][i];
    return f[u][0];
}
int p[N], cnt, resp[N], ans;
int dis(int u, int v) {return d[u]+d[v]-2*d[lca(u, v)];}
int calc(int i)
{
    return dis(p[i-1], p[i])^dis(p[i], p[i+1]);
}
void bfsolve()
{
    rep(i, 1, n) p[i]=i;
    do {
        if(p[1]!=s || p[n]!=t) continue;
        int res=0;
        rep(i, 2, n) res^=dis(p[i-1], p[i]);
        if(res<ans)
        {
            ans=res; rep(i, 1, n) resp[i]=p[i];
        }
    } while(next_permutation(p+1, p+n+1));
    rep(i, 1, n) printf("%d ", resp[i]);
    puts("");
}
void solve()
{
    scanf("%d%d%d", &n, &s, &t);
    ans=2e9; rep(i, 1, n) g[i].clear();
    rep(i, 2, n)
    {
        int u, v; scanf("%d%d", &u, &v);
        g[u].push_back(v), g[v].push_back(u);
    }
    dfs(1, 0);
    if(n<=10) return bfsolve();
    p[1]=s, p[n]=t; cnt=1;
    rep(i, 1, n) if(i!=s && i!=t) p[++cnt]=i;
    int res=0;
    rep(i, 2, n) res^=dis(p[i], p[i-1]);
    while(res>1)
    {
        int i=0, j=0;
        while(i==j) i=rnd(2, n-1), j=rnd(2, n-1);
        res^=calc(i)^calc(j);
        swap(p[i], p[j]);
        res^=calc(i)^calc(j);
    }
    rep(i, 1, n) printf("%d ", p[i]);
    puts("");
}

int main()
{
#ifdef Jerrywang
    freopen("in.txt", "r", stdin);
#endif
    scanf("%d", &T); while(T--) solve();
    return 0;
}