#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <unordered_map>
#include <map>
#include <unordered_set>
#include <queue>
#include <algorithm>
#include <cmath>
#include <set>
#include <queue>
using namespace std;
const int MAX_N = 100500;
const int B = 316;
int n, m, q;
vector<int> adj[MAX_N];
vector<pair<int, int>> paths[MAX_N];
bool is_allowed[MAX_N];
// bool used[MAX_N];
int seen[MAX_N];
int d[MAX_N];
int heavy_ans(int t) {
int ans = -1;
memset(d, -1, sizeof d);
d[t] = 0;
for (int i = t;i >= 0;--i) {
if (is_allowed[i]) {
ans = max(ans, d[i]);
}
if (d[i] == -1) continue;
for (auto to: adj[i]) {
d[to] = max(d[to], d[i] + 1);
}
}
return ans;
}
int main() {
cin.tie(NULL);
ios_base::sync_with_stdio(false);
cin >> n >> m >> q;
for (int i = 0;i < m;++i) {
int f, t;
cin >> f >> t;
--f; --t;
adj[t].push_back(f);
}
int timer = 0;
vector<pair<int, int>> tmp;
for (int i = 0;i < n;++i) {
paths[i].push_back(make_pair(0, i));
for (auto to: adj[i]) {
++timer;
tmp.clear();
int ptr1 = 0, ptr2 = 0;
for (;ptr1 < paths[i].size() && ptr2 < paths[to].size() && tmp.size() <= B;) {
if (seen[paths[i][ptr1].second] == timer) {
++ptr1;
continue;
}
if (seen[paths[to][ptr2].second] == timer) {
++ptr2;
continue;
}
if (paths[i][ptr1].first > paths[to][ptr2].first + 1) {
seen[paths[i][ptr1].second] = timer;
tmp.push_back(paths[i][ptr1++]);
} else {
seen[paths[to][ptr2].second] = timer;
tmp.push_back(make_pair(paths[to][ptr2].first + 1, paths[to][ptr2].second));
++ptr2;
}
}
while (ptr1 < paths[i].size() && tmp.size() <= B) {
if (seen[paths[i][ptr1].second] != timer) {
seen[paths[i][ptr1].second] = timer;
tmp.push_back(paths[i][ptr1]);
}
++ptr1;
}
while (ptr2 < paths[to].size() && tmp.size() <= B) {
if (seen[paths[to][ptr2].second] != timer) {
seen[paths[to][ptr2].second] = timer;
tmp.push_back(make_pair(paths[to][ptr2].first + 1, paths[to][ptr2].second));
}
++ptr2;
}
paths[i] = tmp;
}
}
int t, y;
vector<int> c;
memset(is_allowed, 1, sizeof is_allowed);
for (int i = 0;i < q;++i) {
cin >> t >> y;
--t;
c.resize(y);
for (int i = 0;i < y;++i) {
cin >> c[i];
--c[i];
is_allowed[c[i]] = false;
}
if (y < B) {
int ans = -1;
for (auto [length, id]: paths[t]) {
if (is_allowed[id]) {
ans = length;
break;
}
}
cout << ans << endl;
} else {
cout << heavy_ans(t) << endl;
}
for (int i = 0;i < y;++i) {
is_allowed[c[i]] = true;
}
}
}
