#include <bits/stdc++.h>
using namespace std;
using pii = pair<int,int>;
#define fs first
#define sc second
int n, m, Q, y, ed, ein[510000] = {0}, tt = 1, bad[510000], dp[510000];
int B = 500, vis[510000]={0}, tt2=8;
vector<int> e[510000], topo;
vector<pii> ans[510000];
void bruteforce() {
memset(dp, -63, sizeof(dp));
for (int i : topo) {
if (bad[i] != tt) dp[i] = max(dp[i], 0);
for (int j : e[i]) dp[j] = max(dp[i]+1, dp[j]);
}
}
vector<pii> func(vector<pii> a, vector<pii> b) {
// 類似 merge sort
vector<pii> c;
tt2++;
int i = 0, j = 0;
while (i < a.size() or j < b.size()) {
if (i != a.size() and (j == b.size() or a[i] > b[j])) {
if (vis[a[i].sc] != tt2) {
vis[a[i].sc] = tt2;
c.push_back(a[i]);
}
i++;
}
else {
if (vis[b[j].sc] != tt2) {
vis[b[j].sc] = tt2;
c.push_back(b[j]);
}
j++;
}
}
if (c.size() > B) c.resize(B);
return c;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> m >> Q;
while (m--) {
int x, y;
cin >> x >> y;
e[x].push_back(y);
ein[y]++;
}
queue<int> q;
for (int i = 1; i <= n; i++) if (!ein[i]) q.push(i);
while (q.size()) {
int i = q.front(); q.pop();
topo.push_back(i);
for (int j : e[i]) {
if (!--ein[j]) q.push(j);
}
}
for (int i : topo) {
ans[i] = func(ans[i], vector<pii>(1,make_pair(0,i)));
for (auto &[dis, id] : ans[i]) dis++;
for (int j : e[i]) {
ans[j] = func(ans[j], ans[i]);
}
for (auto &[dis, id] : ans[i]) dis--;
}
while (Q--) {
tt++;
cin >> ed >> y;
vector<int> badv(y);
for (int & x : badv) {
cin >> x;
bad[x] = tt;
}
if (y >= B) {
bruteforce();
if (dp[ed] < 0) dp[ed] = -1;
cout << dp[ed] << '\n';
}
else {
bool y = 0;
for (auto [dis,i] : ans[ed]) {
if (bad[i] == tt) continue;
y = 1;
cout << dis << '\n'; break;
}
if (!y) cout << "-1\n";
}
}
return 0;
}
