#include <bits/stdc++.h>
using i64 = long long;
int main() {
int N, Q;
std::cin >> N >> Q;
std::vector<int> A(N - 1), B(N - 1);
std::vector<std::vector<int>> baseTree(N);
for (int i = 0; i < N - 1; ++i) {
std::cin >> A[i] >> B[i];
--A[i], --B[i];
baseTree[A[i]].push_back(B[i]);
baseTree[B[i]].push_back(A[i]);
}
std::vector<int> D(Q);
std::vector<std::vector<int>> L(Q);
for (int i = 0; i < Q; ++i) {
std::cin >> D[i];
L[i].resize(D[i]);
for (int &e : L[i]) {
std::cin >> e;
--e;
}
}
std::vector<int> degree(N);
for (int i = 0; i < N; ++i) {
degree[i] = (int)baseTree[i].size();
}
const int nonLeafV = (std::max_element(degree.begin(), degree.end()) - degree.begin());
for (int q = 0; q < Q; ++q) {
std::vector<std::vector<int>> tree = baseTree;
for (int i = 0; i < D[q]; ++i) {
const int v = L[q][i];
tree.push_back(std::vector<int>());
tree[N + i].push_back(v);
tree[v].push_back(N + i);
}
auto dfs = [&](auto &&self, const int v, const int p) -> std::pair<i64, int> {
i64 ret = 0;
int cnt = 0;
if (tree[v].size() == 1) {
ret = 0;
cnt = 1;
return {ret, cnt};
}
for (const int t : tree[v]) {
if (p == t) {
continue;
}
const auto [cval, c] = self(self, t, v);
assert(1 <= c and c <= 2);
cnt += c;
ret += cval + c;
}
cnt %= 2;
if (cnt == 0) {
cnt += 2;
}
if (cnt == 1 and v == nonLeafV) {
ret = -1;
}
return {ret, cnt};
};
std::cout << dfs(dfs, nonLeafV, -1).first << std::endl;
}
}
