#include <bits/stdc++.h>
using namespace std;
const int kN = 1e5;
const int bucket = 50;
vector<int> gt[1 + kN];
vector<pair<int, int>> paths[1 + kN];
int ptr[1 + kN], vis[1 + kN], b[kN], dp[1 + kN];
bitset<1 + kN> blocked;
void testCase() {
int n, m, q;
cin >> n >> m >> q;
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
gt[v].emplace_back(u);
}
for (int u = 1; u <= n; ++u) {
priority_queue<tuple<int, int, int>> pq;
pq.emplace(-1, u, -1);
for (int v : gt[u]) {
if (!paths[v].empty()) {
ptr[v] = 0;
pq.emplace(paths[v][0].first, paths[v][0].second, v);
}
}
while (!pq.empty()) {
int len, node, v;
tie(len, node, v) = pq.top();
pq.pop();
if (vis[node] != u) {
paths[u].emplace_back(len + 1, node);
vis[node] = u;
}
if (v == -1) {
continue;
}
ptr[v] += 1;
if (ptr[v] < (int)paths[v].size()) {
pq.emplace(paths[v][ptr[v]].first, paths[v][ptr[v]].second, v);
}
}
}
for (int i = 0; i < q; ++i) {
int s, m;
cin >> s >> m;
for (int j = 0; j < m; ++j) {
cin >> b[j];
blocked[b[j]] = true;
}
if (bucket <= m) {
for (int u = 1; u <= n; ++u) {
if (blocked[u]) {
dp[u] = -1;
} else {
dp[u] = 0;
}
for (int v : gt[u]) {
if (dp[v] != -1 && dp[u] < dp[v] + 1) {
dp[u] = dp[v] + 1;
}
}
}
cout << dp[s] << '\n';
} else {
int ans = -1;
for (auto it : paths[s]) {
if (!blocked[it.second]) {
ans = it.first;
break;
}
}
cout << ans << '\n';
}
for (int j = 0; j < m; ++j) {
blocked[b[j]] = false;
}
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int tests = 1;
for (int tc = 0; tc < tests; ++tc) {
testCase();
}
return 0;
}
