#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
const int maxN = 1e5;
const int blockSize = 2;
typedef pair<int, int> ii;
int n, m, q;
int dp[maxN + 5];
vector<int> pre[maxN + 5];
vector<ii> root[maxN + 5];
bool maximize(int &x, int y){
return (y > x ? x = y, 1 : 0);
}
void build(){
vector<int> cost(n + 5, 0);
vector<int> visited(n + 5, -1);
for (int i = 1; i <= n; ++i){
vector<int> r;
for (int j : pre[i]){
for (auto e : root[j]){
int k = e.x, c = e.y;
if (visited[k] == i)
maximize(cost[k], c + 1);
else{
r.push_back(k);
cost[k] = c + 1;
visited[k] = i;
}
}
if (visited[j] != i){
r.push_back(j);
cost[j] = 1;
visited[j] = i;
}
}
r.push_back(i);
sort(r.begin(), r.end(), [&](int a, int b){
return (cost[a] > cost[b]);
});
int sz = min(int(r.size()), blockSize);
for (int j = 0; j < sz; ++j){
int p = r[j];
root[i].push_back({p, cost[p]});
}
}
}
int main(){
ios::sync_with_stdio(0); cin.tie(0);
cin >> n >> m >> q;
for (int i = 1; i <= m; ++i){
int u, v; cin >> u >> v;
pre[v].push_back(u);
}
build();
vector<int> queries(n + 5, 0);
for (int i = 1; i <= q; ++i){
int t; cin >> t;
int sz; cin >> sz;
for (int j = 1; j <= sz; ++j){
int x; cin >> x;
queries[x] = i;
}
if (sz < blockSize){
bool f = 0;
for (auto e : root[t]){
if (queries[e.x] == i) continue;
cout << e.y << '\n';
f = 1;
break;
}
if (!f) cout << -1 << '\n';
}
else{
for (int j = 1; j <= n; ++j){
if (queries[j] != i) dp[j] = 0;
else dp[j] = -1;
for (int k : pre[j])
if (dp[k] >= 0) maximize(dp[j], dp[k] + 1);
}
cout << dp[t] << '\n';
}
}
return 0;
}
