This documentation is automatically generated by online-judge-tools/verification-helper
#define PROBLEM \
"https://onlinejudge.u-aizu.ac.jp/courses/library/5/GRL/5/GRL_5_C"
// clang-format off
#include "../template/template.cpp"
#include "../graph/lca-doubling.cpp"
// clang-format on
void Main() {
int n = in();
vvint g(n);
rep(i, n) {
int k = in();
rep(j, k) {
int c = in();
g[i].pb(c);
g[c].pb(i);
}
}
DoublingLowestCommonAncestor<vvint> lca(g);
int q = in();
while (q--) {
int u = in(), v = in();
out(lca.query(u, v));
}
}
#line 1 "test/lca-doubling.test.cpp"
#define PROBLEM \
"https://onlinejudge.u-aizu.ac.jp/courses/library/5/GRL/5/GRL_5_C"
// clang-format off
#line 1 "template/template.cpp"
#include <algorithm>
#include <array>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdint>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
#ifdef _DEBUG
#define DUMP(x) std::cerr << (#x) << " = " << (x) << "\n"
#else
#define DUMP(x)
#endif
#define REP(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define EREP(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define RREP(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rep(i, n) REP(i, 0, n)
#define erep(i, n) EREP(i, 0, n)
#define rrep(i, n) RREP(i, n, 0)
#define ALL(r) (r).begin(), (r).end()
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
os << "{";
rep(i, v.size()) os << v[i] << (i == (int)v.size() - 1 ? "" : ", ");
os << "}";
return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
return (os << "(" << p.first << ", " << p.second << ")");
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &m) {
bool first = true;
os << "{";
for (const auto &e : m) {
if (!first)
os << ", ";
os << "{" << e.first << ": " << e.second << "}";
first = false;
}
os << "}";
return os;
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &s) {
os << "{";
bool first = true;
for (const auto &e : s) {
if (!first)
os << ", ";
os << e;
first = false;
}
os << "}";
return os;
}
template <typename T>
ostream &operator<<(ostream &os, const multiset<T> &s) {
os << "{";
bool first = true;
for (const auto &e : s) {
if (!first)
os << ", ";
os << e;
first = false;
}
os << "}";
return os;
}
template <typename T>
T dup(T x, T y) {
return (x + y - 1) / y;
};
template <typename A, size_t N, typename T>
inline void arrayFill(A (&array)[N], const T &val) {
std::fill((T *)array, (T *)(array + N), val);
}
template <class T>
inline bool chmax(T &a, T b) {
if (a < b) {
a = b;
return true;
}
return false;
}
template <class T>
inline bool chmin(T &a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
struct in {
const size_t n = 0;
in() = default;
in(size_t n) : n(n){};
template <typename T>
operator T() {
T ret;
cin >> ret;
return ret;
}
template <typename T>
operator vector<T>() {
assert(n != 0);
vector<T> ret(n);
for (T &x : ret) {
T tmp = in();
x = tmp;
}
return ret;
}
template <typename T, typename U>
operator pair<T, U>() {
pair<T, U> ret;
ret.first = in();
ret.second = in();
return ret;
}
};
namespace fiore {
namespace impl {
template <typename T>
inline void out_impl(const T &x, char end_char) {
std::cout << x << end_char;
}
template <typename T>
inline void out_impl(const vector<T> &x, char end_char) {
bool first = true;
for (const auto &e : x) {
if (!first)
std::cout << ' ';
std::cout << e;
first = false;
}
std::cout << end_char;
}
} // namespace impl
} // namespace fiore
template <typename T>
inline void out(const T &x) {
fiore::impl::out_impl(x, '\n');
};
template <typename T, typename U, typename... Args>
inline void out(const T &x, const U &y, const Args &... args) {
fiore::impl::out_impl(x, ' ');
out(y, args...);
}
using ll = int64_t;
using vint = vector<int32_t>;
using vvint = vector<vint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vstr = vector<string>;
using pint = pair<int32_t, int32_t>;
using vpint = vector<pint>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using setint = set<int32_t>;
using qint = queue<int32_t>;
using qpint = queue<pint>;
constexpr std::int32_t INF = 1001001001;
constexpr std::int64_t LINF = 1001001001001001001;
void Main();
signed main() {
std::cin.tie(nullptr);
std::ios_base::sync_with_stdio(false);
std::cout << std::fixed << std::setprecision(15);
Main();
return 0;
}
#line 1 "graph/lca-doubling.cpp"
template <typename G>
class DoublingLowestCommonAncestor {
const G &g;
vector<int> depth;
const int LOG;
vector<vector<int>> table;
public:
explicit DoublingLowestCommonAncestor(const G &g)
: g(g), depth(g.size()), LOG(32 - __builtin_clz(g.size())) {
table.assign(LOG, vector<int>(g.size(), -1));
build();
}
int query(int u, int v) const {
if (depth[u] > depth[v])
swap(u, v);
for (int i = LOG - 1; i >= 0; --i) {
if (((depth[v] - depth[u]) >> i) & 1)
v = table[i][v];
}
if (u == v)
return u;
for (int i = LOG - 1; i >= 0; --i) {
if (table[i][u] != table[i][v]) {
u = table[i][u];
v = table[i][v];
}
}
return table[0][u];
}
int get_dist(const int u, const int v) const {
return depth[u] + depth[v] - 2 * depth[query(u, v)];
}
bool is_on_path(const int u, const int v, const int a) const {
return get_dist(u, a) + get_dist(a, v) == get_dist(u, v);
}
private:
void build() {
dfs(0, -1, 0);
for (int k = 0; k + 1 < LOG; k++) {
const int sz = table[k].size();
for (int i = 0; i < sz; ++i) {
if (table[k][i] == -1)
table[k + 1][i] = -1;
else
table[k + 1][i] = table[k][table[k][i]];
}
}
}
void dfs(const int idx, const int par, const int d) {
table[0][idx] = par;
depth[idx] = d;
for (const auto &to : g[idx]) {
if (to != par)
dfs(to, idx, d + 1);
}
}
};
#line 6 "test/lca-doubling.test.cpp"
// clang-format on
void Main() {
int n = in();
vvint g(n);
rep(i, n) {
int k = in();
rep(j, k) {
int c = in();
g[i].pb(c);
g[c].pb(i);
}
}
DoublingLowestCommonAncestor<vvint> lca(g);
int q = in();
while (q--) {
int u = in(), v = in();
out(lca.query(u, v));
}
}