#include <bits/stdc++.h>
#pragma GCC optimize("O3","unroll-loops")
#pragma GCC target("avx2","popcnt","sse4","abm")
using namespace std;
#ifdef MIKU
string dbmc = "\033[1;38;2;57;197;187m", dbrs = "\033[0m";
#define debug(x...) cout << dbmc << "[" << #x << "]: ", dout(x)
void dout() { cout << dbrs << endl; }
template <typename T, typename ...U>
void dout(T t, U ...u) { cout << t << (sizeof...(u) ? ", " : ""); dout(u...); }
#else
#define debug(...) 39
#endif
#define fs first
#define sc second
#define mp make_pair
#define FOR(i, j, k) for (int i = j, Z = k; i < Z; i++)
using ll = long long;
typedef pair<int, int> pii;
const int MXN = 100005, K = 280, INF = 1e9;
int n, m, q;
vector<int> edge[MXN], edge_inv[MXN];
bitset<MXN> b;
int dis[MXN];
vector<pii> w[MXN];
void MERGE(vector<pii> &a, vector<pii> &b, vector<pii> &c) {
c.clear();
for (int i = 0, j = 0; i < a.size() || j < b.size(); ) {
if (i == a.size()) c.push_back(b[j++]);
else if (j == b.size()) c.push_back(a[i++]);
else if (a[i].sc < b[i].sc) c.push_back(b[j++]);
else c.push_back(a[i++]);
}
}
void DP(int id) {
vector<pii> a, bb, c;
a.push_back(mp(id, 0));
for (auto pre : edge_inv[id]) {
for (auto [id, len] : w[pre]) bb.push_back(mp(id, len + 1));
MERGE(a, bb, c);
a.clear();
bb.clear();
for (auto [id, len] : c) {
if (b[id]) continue;
a.push_back(mp(id, len));
}
while (a.size() > K + 1) a.pop_back();
}
w[id] = a;
}
void TS(int sr) {
fill(dis + 1, dis + n + 1, -INF);
dis[sr] = 0;
for (int id = sr - 1; id; id--) {
for (auto &i : edge[id]) dis[id] = max(dis[id], dis[i] + 1);
}
}
int calc(int t, vector<int> &v) {
if (v.size() <= K) {
for (auto [i, x] : w[t]) {
if (b[i]) continue;
return x;
}
return -1;
} else {
TS(t);
int ans = -1;
FOR(i, 1, t + 1) {
if (b[i]) continue;
ans = max(ans, dis[i]);
}
return ans;
}
return 0;
}
void miku() {
cin >> n >> m >> q;
while (m--) {
int x, y;
cin >> x >> y;
edge[x].push_back(y);
edge_inv[y].push_back(x);
}
FOR(i, 1, n + 1) DP(i);
while (q--) {
int t, y;
vector<int> v;
cin >> t >> y;
v.resize(y);
for (auto &i : v) {
cin >> i;
b[i] = true;
}
cout << calc(t, v) << '\n';
for (auto &i : v) {
b[i] = false;
}
}
// FOR(i, 1, n + 1) {
// debug(i);
// for (auto &[id, x] : w[i]) debug(id, x);
// }
}
int32_t main() {
cin.tie(0) -> sync_with_stdio(false);
cin.exceptions(cin.failbit);
miku();
return 0;
}
