#include <bits/stdc++.h>
#define N 200005
#define BL 317
using namespace std;
typedef pair<int, int> pi;
int n, m, q;
vector<int> paths[N], NOT;
set<pi> dp[N], alr[N];
bool visited[N];
void dfs(int cur) {
visited[cur] = 1;
for(int i: paths[cur]) {
for(auto&[v, ind]: dp[cur]) {
auto alrin = alr[i].lower_bound(pi(ind, 0));
if(alrin != alr[i].end() && (*alrin).first == ind) {
dp[i].erase(pi((*alrin).second, -(*alrin).first));
alr[i].erase(alrin);
}
if(dp[i].size() == BL) {
if(v - 1 < (*prev(dp[i].end())).first) {
dp[i].erase(prev(dp[i].end()));
} else {
break;
}
}
dp[i].insert({v-1, ind});
alr[i].insert({ind, -v + 1});
}
}
}
int ANS[N];
bool allowed[N];
void DP(int cur) {
visited[cur] = 1;
if(ANS[cur] == -1) return;
for(int i: paths[cur]) {
ANS[i] = max(ANS[i], ANS[cur] + 1);
}
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m >> q;
for(int i = 1; i <= n; i ++) {
dp[i].insert({0, i});
}
while(m--) {
int a, b;
cin >> a >> b;
paths[a].push_back(b);
}
for(int i = 1; i <= n; i ++) {
if(!visited[i]) dfs(i);
allowed[i] = 1;
}
while(q--) {
int a, b;
cin >> a >> b;
NOT.resize(b);
for(auto&i: NOT) {
cin >> i;
allowed[i] = 0;
}
if(b > BL) {
for(auto&i: ANS) i = 0;
for(auto i: NOT) ANS[i] = -1;
for(auto&i: visited) i = 0;
for(int i = 1; i <= n; i ++) {
if(!visited[i]) DP(i);
}
cout << ANS[a] << "\n";
} else {
bool added = true;
for(auto&[v, i]: dp[a]) {
if(allowed[i]) {
added = false;
cout << (-v) << "\n";
break;
}
}
if(added) cout << -1 << "\n";
}
for(auto&i: NOT) allowed[i] = 1;
}
}
