/**
* author: Jotinha (ツ)
* created: 02-28-2025 11:09:44
**/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "algo/debug.h"
#else
#define debug(...) 42
#endif
vector<pair<int, vector<int>>> qr[100005];
pair<int, int> dp[100005][318];
void countingSort(vector<int>& arr, int mn = 0, int mx = 100000){
int i,k=0,sizeTemp = mx-mn+1;
int temp[sizeTemp];
// Initializing all element of counting array with 0
for(i=0; i<sizeTemp; i++){
temp[i] = 0;
}
//Store the frequency of each element of the original array
//at the relative position in counting array
for(i=0; i< (int) arr.size(); i++){
temp[arr[i]-mn]++;
}
//Iterate through the counting array and re-write the original array.
for (i=mx; i>=mn; i--){
while(temp[i-mn]-->0){
arr[k++]=i;
}
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, m, q;
cin >> n >> m >> q;
vector<vector<int>> g(n);
for(int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
--u, --v;
if(u < v) {
swap(u, v);
}
g[u].push_back(v);
}
vector<int> tot(n);
int t = 0;
for(int i = 0; i < q; i++) {
int u, k;
cin >> u >> k;
--u;
vector<int> v(k);
for(int& j : v) {
cin >> j;
--j;
}
qr[u].emplace_back(make_pair(t++, v));
tot[u] += (int) v.size();
}
auto bfs = [&](int u) {
vector<int> dist(n, -1);
queue<int> qe;
qe.emplace(u);
dist[u] = 0;
while(!qe.empty()) {
auto v = qe.front();
qe.pop();
for(int nxt : g[v]) {
if(dist[nxt] < dist[v] + 1) {
dist[nxt] = dist[v] + 1;
qe.push(nxt);
}
}
}
return dist;
};
const int sq = 280;
const int inf = 0x3f3f3f3f;
for(int i = 0; i < n; i++) {
for(int j = 0; j < sq; j++) {
dp[i][j] = {-inf, inf};
}
}
vector<int> vis(n);
function<void(int)> dfs = [&](int u) {
if(vis[u]) {
return;
}
vector<pair<int, int>> wait { {0, u} };
for(int nxt : g[u]) {
dfs(nxt);
for(int i = 0; i < sq && dp[nxt][i].first >= 0; i++) {
wait.emplace_back(dp[nxt][i].first + 1, dp[nxt][i].second);
}
}
sort(wait.rbegin(), wait.rend());
wait.erase(unique(wait.begin(), wait.end()), wait.end());
for(int i = 0; i < sq && i < (int) wait.size(); i++) {
dp[u][i] = wait[i];
}
vis[u] = 1;
};
vector<int> ans(t, -2);
for(int i = n - 1; i >= 0; i--) {
if(tot[i] >= sq) {
auto dist = bfs(i);
auto d2 = dist;
for(int j = 0; j < n; j++) {
d2[j] += 1;
}
countingSort(d2);
for(int j = 0; j < qr[i].size(); j++) {
sort(qr[i][j].second.begin(), qr[i][j].second.end(), [&](int x, int y) {
return dist[x] > dist[y];
});
int ge = 1;
for(int k = 0; k < (int) qr[i][j].second.size(); k++) {
if(dist[qr[i][j].second[k]] != d2[k] - 1) {
ans[qr[i][j].first] = d2[k] - 1;
ge = 0;
break;
}
}
if(ge) {
if((int) qr[i][j].second.size() == n) {
ans[qr[i][j].first] = -1;
} else {
ans[qr[i][j].first] = d2[(int) qr[i][j].second.size()] - 1;
}
}
}
} else {
dfs(i);
for(int j = 0; j < sq; j++) {
for(int k = 0; k < qr[i].size(); k++) {
if(ans[qr[i][k].first] == -2) {
int show = 1;
for(int nxt : qr[i][k].second) {
if(nxt == dp[i][j].second) {
show = 0;
break;
}
}
if(show) {
ans[qr[i][k].first] = dp[i][j].first;
}
}
}
}
}
}
for(int x : ans) {
cout << (x < 0 ? -1 : x) << '\n';
}
return 0;
}
