#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> g, rg;
vector<vector<pair<int, int>>> path;
vector<int> dp, mark;
int n, m, q;
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m >> q;
g.assign(n+2, vector<int>());
rg.assign(n+2, vector<int>());
path.assign(n+2, vector<pair<int, int>>());
mark.assign(n+2, -1);
while(m--) {
int u, v;
cin >> u >> v;
if(u > v) swap(u, v);
g[u].push_back(v);
rg[v].push_back(u);
}
for(int i=1; i<=n; i++) {
path[i].push_back({0, i});
vector<int> idx;
mark[i] = 0;
idx.push_back(i);
for(auto j: rg[i]) {
for(auto k: path[j]) {
if(mark[k.second] == -1) idx.push_back(k.second);
mark[k.second] = max(mark[k.second], k.first+1);
}
}
for(auto j: idx) {
path[i].push_back({mark[j], j});
}
sort(path[i].begin(), path[i].end(), greater<pair<int, int>>());
while(path[i].size() > 100) {
path[i].pop_back();
}
for(auto i: idx) {
mark[i] = -1;
}
}
mark.assign(n+2, -1);
while(q--) {
int t, y;
set<int> blk;
cin >> t >> y;
for(int i=1; i<=y; i++) {
int in;
cin >> in;
mark[in] = 1;
blk.insert(in);
}
if(y >= 100) {
dp.assign(n+2, -1);
for(int i=1; i<=t; i++) {
if(mark[i] == -1) dp[i] = max(dp[i], 0);
if(dp[i] == -1) continue;
for(auto j: g[i]) {
dp[j] = max(dp[j], dp[i]+1);
}
}
cout << dp[t] << "\n";
} else {
vector<pair<int, int>> v = path[t];
int ans = -1;
for(auto i: v) {
if(mark[i.second] == -1) {
ans = max(ans, i.first);
}
}
cout << ans << "\n";
}
for(auto i: blk) mark[i] = -1;
}
}
