#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9 + 7;
const int MAXN = 1e5 + 10;
const int SQRT = 0;
vector<int> adj[MAXN];
int n, m, q;
int dp[MAXN];
bool seen[MAXN];
bool bad[MAXN];
void build() {
return;
}
void dfs_large(int v, int target) {
seen[v] = true;
if (v == target) dp[v] = 0;
for (int w: adj[v]) {
if (!seen[w]) dfs_large(w, target);
dp[v] = max(dp[v], dp[w] + 1);
}
}
int solve_small(int target, vector<int> &busy) {
return -INF;
}
int solve_large(int target, vector<int> &busy) {
for (int i = 1; i <= n; i++) {
seen[i] = false;
bad[i] = false;
dp[i] = -INF;
}
for (int x: busy) {
bad[x] = true;
}
int resp = -1;
for (int i = 1; i <= n; i++) {
if (!bad[i]) {
dfs_large(i, target);
resp = max(resp, dp[i]);
}
}
return resp;
}
int query(int target, vector<int> &busy) {
int sz = (int) busy.size();
if (sz <= SQRT) return solve_small(target, busy);
else return solve_large(target, busy);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m >> q;
while (m--) {
int a, b; cin >> a >> b;
adj[a].push_back(b);
}
build();
while (q--) {
int t, cnt; cin >> t >> cnt;
vector<int> busy;
while (cnt--) {
int x; cin >> x;
busy.push_back(x);
}
cout << query(t, busy) << endl;
}
return 0;
}
