#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = 1e9 + 7;
const int SQRT = 300;
// bitarooo
signed main() {
cin.tie(0); ios::sync_with_stdio(false);
int N, M, Q;
cin >> N >> M >> Q;
vector<vector<int>> adj(N); // reversed
for(int i = 0; i < M; i++) {
int a, b;
cin >> a >> b;
a--; b--;
adj[b].push_back(a);
}
vector<vector<pair<int,int>>> dp(N);
vector<pair<int,int>> idx(N, {-1, -1});
for(int v = 0; v < N; v++) {
dp[v].push_back({0, v});
for(int &u: adj[v]) {
for(auto &[dist, start]: dp[u]) { // MsqrtN
if (idx[start].first != v) {
dp[v].push_back({dist + 1, start});
idx[start] = {v, dp[v].size() - 1};
} else dp[v][idx[start].second].first = max(dp[v][idx[start].second].first, dist + 1);
}
}
sort(dp[v].begin(), dp[v].end());
reverse(dp[v].begin(), dp[v].end());
while(dp[v].size() > SQRT) dp[v].pop_back();
}
vector<int> cant(N, -1);
vector<int> dp2;
for(int i = 0; i < Q; i++) {
int t, y;
cin >> t >> y;
t--;
for(int j = 0; j < y; j++) {
int x;
cin >> x;
x--;
cant[x] = i;
}
if (y < SQRT) {
bool yes = false;
for(int k = 0; k < dp[t].size(); k++) {
if (cant[dp[t][k].second] != i) {
yes = true;
cout << dp[t][k].first << endl;
break;
}
}
if (!yes) cout << -1 << endl;
} else {
dp2.assign(N, -INF);
for(int v = 0; v <= t; v++) {
if (cant[v] != i) dp2[v] = 0;
for(int &u: adj[v]) {
if (dp2[u] != -INF) dp2[v] = max(dp2[v], dp2[u] + 1);
}
}
if (dp2[t] != -INF) cout << dp2[t] << endl;
else cout << -1 << endl;
}
}
}
