lca

#include <bits/stdc++.h>

using namespace std;

int t, n, l, q;
vector<vector<int>> adj, up;
vector<int> tin, tout, h;

void dfs(int v, int p = 1, int hh = 0) {
    tin[v] = ++t;
    up[v][0] = p;
    for(int i = 1; i <= l; i++) {
        up[v][i] = up[up[v][i - 1]][i - 1];
    }
    for(auto u : adj[v]) {
        if(u != p) {
            dfs(u, v, hh + 1);
        }
    }
    h[v] = hh;
    tout[v] = ++t;
}

bool isanc(int u, int v) {
    return tin[u] <= tin[v] and tout[u] >= tout[v];
}

int lca(int u, int v) {
    if(isanc(u, v)) {
        return u;
    }
    if(isanc(v, u)) {
        return v;
    }
    for(int i = l; i >= 0; i--) {
        if(!isanc(up[u][i], v)) {
            u = up[u][i];
        }
    }
    return up[u][0];
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int tt;
    cin >> tt;
    for(int ii = 1; ii <= tt; ii++) {
        cout << "Case " << ii << ":\n";
        t = 0;
        int n;
        cin >> n;
        tin.clear(); tin.resize(n + 1);
        tout.clear(); tout.resize(n + 1);
        h.clear(); h.resize(n + 1);
        adj.clear(); adj.resize(n + 1);
        l = ceil(log2(n + 1)) + 1;
        up.clear(); up.assign(n + 1, vector<int>(l + 1));
        for(int i = 1; i <= n; i++) {
            int x;
            cin >> x;
            while(x--) {
                int u;
                cin >> u;
                adj[i].push_back(u);
                adj[u].push_back(i);
            }
        }
        dfs(1);
        cin >> q;
        while(q--) {
            int u, v;
            cin >> u >> v;
            cout << lca(u, v) << "\n";
        }
    }
    return 0;
}