#include <bits/stdc++.h>
using namespace std;
const int N = 5e4 + 10;

mt19937 rnd(random_device{}());
inline int RD(int l, int r) { return rnd() % (r - l + 1) + l; }

int n, s, t, p[N], fa[N], son[N], siz[N], dep[N], top[N];
vector<int> g[N];

void dfs1(int x, int Fa) {
    dep[x] = dep[fa[x] = Fa] + (siz[x] = 1), son[x] = 0;
    for (int y : g[x]) if (y != Fa) {
        dfs1(y, x), siz[x] += siz[y];
        if (siz[son[x]] < siz[y]) son[x] = y;
    }
}
void dfs2(int x, int Top) {
    top[x] = Top;
    if (son[x]) dfs2(son[x], Top);
    for (int y : g[x]) if (y != fa[x] && y != son[x]) dfs2(y, y);
}
inline int LCA(int x, int y) {
    while (top[x] != top[y]) dep[top[x]] < dep[top[y]] ? y = fa[top[y]] : x = fa[top[x]];
    return dep[x] < dep[y] ? x : y;
}
inline int dis(int x, int y) { return dep[x] + dep[y] - (dep[LCA(x, y)] << 1); }

inline void solve() {
    scanf("%d%d%d", &n, &s, &t);
    for (int i = 1; i <= n; ++i) g[i].clear();
    for (int i = 1, u, v; i < n; ++i) scanf("%d%d", &u, &v);
    dfs1(1, 0), dfs2(1, 1);
    p[1] = s, p[n] = t;
    for (int i = 1, x = 1; i <= n; ++i) if (i != s && i != t) p[++x] = i;
    int ans = 0, Ans = 0;
    for (int i = 1; i < n; ++i) ans ^= dis(p[i], p[i + 1]);
    Ans = ans;
    for (int tim = n * 60; tim-- && Ans > 1;) {
        if (n < 4) break;
        int x = RD(2, n - 1), y = RD(2, n - 1);
        while (x == y) y = RD(2, n - 1);
        ans ^= dis(p[x - 1], p[x]) ^ dis(p[x], p[x + 1]);
        ans ^= dis(p[y - 1], p[y]) ^ dis(p[y], p[y + 1]);
        swap(p[x], p[y]);
        ans ^= dis(p[x - 1], p[x]) ^ dis(p[x], p[x + 1]);
        ans ^= dis(p[y - 1], p[y]) ^ dis(p[y], p[y + 1]);
        Ans = min(Ans, ans);
    }
    for (int i = 1; i <= n; ++i) printf("%d ", p[i]);
    puts("");
}

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