#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define pb push_back
#define eb emplace_back
#define rz resize
#define MP make_pair
#define MT make_tuple
#define IT iterator
#define fi first
#define se second
#define For(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define Rep(i, a, b) for (int i = (int)(a); i >= (int)(b); --i)
#define CLR(a, v) memset(a, v, sizeof(a))
#define CPY(a, b) memcpy(a, b, sizeof(a))
#define debug cerr << "ztxakking\n"
#define y0 ztxaknoi
#define y1 ztxakioi
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using uint = unsigned int;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pli = pair<ll, int>;
using pil = pair<int, ll>;
using vi = vector<int>;
template<typename T>
using V = vector<T>;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
const int N = 5e4 + 7, Inf = 0x3f3f3f3f;
int n, s, t, dfn[N], dep[N], lis[N], fa[N], timer, ans[N];
vi G[N];
#define Bit(x) (31 - __builtin_clz(x))
struct SparseTable {
  int arr[16][N];
  void init() {
    For(i, 1, n) arr[0][i] = lis[i];
    For(i, 1, Bit(n)) For(j, 1, n - (1 << i) + 1) {
      arr[i][j] = dep[arr[i - 1][j]] <= dep[arr[i - 1][j + (1 << i - 1)]]? arr[i - 1][j] : arr[i - 1][j + (1 << i - 1)];
    }
  }
  int qry(int l, int r) {
    int t = Bit(r - l + 1);
    return dep[arr[t][l]] <= dep[arr[t][r - (1 << t) + 1]]? arr[t][l] : arr[t][r - (1 << t) + 1];
  }
} A;
void dfs(int u) {
  dep[u] = dep[fa[u]] + 1, lis[dfn[u] = ++timer] = u;
  for (int v : G[u]) {
    if (v == fa[u]) continue;
    fa[v] = u, dfs(v);
  }
}
int lca(int u, int v) {
  if (u == v) return u;
  if ((u = dfn[u]) > (v = dfn[v])) swap(u, v);
  return fa[A.qry(u + 1, v)];
}
int dist(int u, int v) {
  return dep[u] + dep[v] - dep[lca(u, v)] * 2;
}
namespace BruteForce {
  int p[N], mi;
  void main() {
    if (n == 2) {
      ans[1] = s, ans[2] = t;
      return ;
    }
    mi = Inf;
    int cur = 0;
    For(i, 1, n) if (i != s && i != t) p[++cur] = i;
    do {
      int w = dist(s, p[1]) ^ dist(p[n - 2], t);
      For(i, 1, n - 3) w ^= dist(p[i], p[i + 1]);
      if (w < mi) {
        mi = w;
        ans[1] = s, ans[n] = t;
        For(i, 2, n - 1) ans[i] = p[i - 1];
      }
    } while (next_permutation(p + 1, p + n - 1));
  }
}
namespace Chrysanthemum {
  void main() {
    ans[1] = s, ans[n] = t;
    int cur = 1;
    For(i, 2, n - 1) {
      while (cur == s || cur == t) ++cur;
      ans[i] = cur;
    }
  }
}
namespace Random {
  int p[N];
  void main() {
    int cur = 1;
    For(i, 1, n) if (i != s && i != t) p[++cur] = i;
    shuffle(p + 2, p + n, rnd);
    p[1] = s, p[n] = t;
    int w = 0;
    For(i, 1, n - 1) w ^= dist(p[i], p[i + 1]);
    while (w > 1) {
      int x, y;
      do {
        x = rnd() % (n - 2) + 2, y = rnd() % (n - 2) + 2;
      } while (x == y);
      if (x > y) swap(x, y);
      if (x == y - 1) {
        w ^= dist(p[x - 1], p[x]) ^ dist(p[y], p[y + 1]);
        swap(p[x], p[y]);
        w ^= dist(p[x - 1], p[x]) ^ dist(p[y], p[y + 1]);
      } else {
        w ^= dist(p[x - 1], p[x]) ^ dist(p[x], p[x + 1]) ^ dist(p[y - 1], p[y]) ^ dist(p[y], p[y + 1]);
        swap(p[x], p[y]);
        w ^= dist(p[x - 1], p[x]) ^ dist(p[x], p[x + 1]) ^ dist(p[y - 1], p[y]) ^ dist(p[y], p[y + 1]);
      }
    }
    For(i, 1, n) ans[i] = p[i];
  }
}
void Main() {
  cin >> n >> s >> t;
  For(i, 1, n) G[i].clear();
  For(i, 1, n - 1) {
    int u, v; cin >> u >> v, G[u].pb(v), G[v].pb(u);
  }
  dfs(1), A.init();
  int mx = 0;
  For(i, 1, n) mx = max(mx, (int)(G[i].size()));
  if (n <= 9) BruteForce::main();
  else if (mx == n - 1) Chrysanthemum::main();
  else Random::main();
  For(i, 1, n) cout << ans[i] << ' ';
  cout << '\n';
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0);
  int t; cin >> t;
  while (t--) Main();
  cerr << (double)(clock()) / CLOCKS_PER_SEC << '\n';
  return 0;
}