#include <bits/stdc++.h>
#define hash _hash_
#define y1 _y1_
#define left _left_
#define right _right_
#define dec _dec_
using namespace std;
using ll = long long;
/*----------- I alone decide my fate! ------------*/
/* I just do what I gotta, in the heat of the summer... */
const int MAXN = 100000 + 5;
const int B = 320; // v(SYj) ˜ 320
int N, M, Q;
vector<int> adj[MAXN], radj[MAXN];
vector<pair<int,int>> best[MAXN]; // (len, start), gi?m d?n theo len
bool ban[MAXN]; // d?nh b?n
int dp[MAXN]; // dùng cho truy v?n n?ng
bool vis_dp[MAXN]; // c? “dã tính dp[u]”
/// G?p best[src] (dã s?p gi?m d?n) vào best[dst], c?ng len+1
void merge_into(vector<pair<int,int>> &dst,
const vector<pair<int,int>> &src)
{
static pair<int,int> buf[2 * B];
int i = 0, j = 0, p = 0;
int na = dst.size(), nb = src.size();
while ((i < na || j < nb) && p < B) {
pair<int,int> cand;
if (j == nb ||
(i < na && dst[i].first >= src[j].first + 1))
{
cand = dst[i++];
} else {
cand = {src[j].first + 1, src[j].second};
++j;
}
// lo?i trùng start
bool dup = false;
for (int k = 0; k < p; ++k) {
if (buf[k].second == cand.second) {
dup = true;
break;
}
}
if (!dup) buf[p++] = cand;
}
dst.assign(buf, buf + p);
}
/// Tính dp[u] = du?ng di dài nh?t k?t thúc ? u, b? qua các u b? ban
int calc(int u) {
if (vis_dp[u]) return dp[u];
vis_dp[u] = true;
dp[u] = ban[u] ? INT_MIN/2 : 0;
for (int v: radj[u]) {
int t = calc(v);
dp[u] = max(dp[u], t + 1);
}
return dp[u];
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> N >> M >> Q;
for (int i = 0; i < M; ++i) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
radj[v].push_back(u);
}
// 1) Kh?i t?o best[u] v?i (len=0, start=u)
for (int u = 1; u <= N; ++u) {
best[u].push_back({0, u});
}
// 2) Ti?n x? lý cho truy v?n “nh?”
// Duy?t topo (1..N) vì d? th? DAG (S < E)
for (int u = 1; u <= N; ++u) {
for (int v: adj[u]) {
merge_into(best[v], best[u]);
}
}
vector<int> busy_list;
while (Q--) {
int T, Y;
cin >> T >> Y;
busy_list.clear();
for (int i = 0; i < Y; ++i) {
int x;
cin >> x;
ban[x] = true;
busy_list.push_back(x);
}
int answer = -1;
if (Y < B) {
// --- truy v?n nh? ---
for (auto &p: best[T]) {
if (!ban[p.second]) {
answer = p.first;
break;
}
}
} else {
// --- truy v?n n?ng ---
// reset c? vis_dp[]
fill(vis_dp+1, vis_dp+N+1, false);
int res = calc(T);
answer = (res < 0 ? -1 : res);
}
cout << answer << "\n";
// xoá dánh d?u ban[]
for (int x: busy_list) {
ban[x] = false;
}
}
return 0;
}
