#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = (int) 1e9 + 1e6 + 123;
const ll LINF = (ll) 1e18 + 1e9 + 123;
#define rep(i, s, t) for (auto i = (s); i < (t); ++(i))
#define per(i, s, t) for (auto i = (s); i >= (t); --(i))
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define mp make_pair
#define pb push_back
bool mini(auto &x, const auto &y) {
if (y < x) {
x = y;
return 1;
}
return 0;
}
bool maxi(auto &x, const auto &y) {
if (y > x) {
x = y;
return 1;
}
return 0;
}
void run();
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
run();
return 0;
}
const int N = (int) 1e5 + 123;
const int K = 300;
int n, m, q;
vector<int> g[N];
int ans[N];
int t[N], y[N];
vector<int> c[N];
int dp[N];
int naive(int id) {
fill(dp, dp + N, 0);
for (int v : c[id]) {
dp[v] = -INF;
}
rep(i, 1, n + 1) {
for (int j : g[i]) {
if (dp[j] != -INF) {
maxi(dp[i], dp[j] + 1);
}
}
}
return (dp[t[id]] == -INF ? -1 : dp[t[id]]);
}
bool used[N];
int cnt[N];
pair<int, int> best[N][K];
pair<int, int> tmp[2 * K];
int small(int id) {
for (int v : c[id]) {
used[v] = 1;
}
int res = -INF;
rep(i, 0, cnt[t[id]]) {
auto &it = best[t[id]][i];
if (!used[it.second]) {
maxi(res, it.first);
}
}
for (int v : c[id]) {
used[v] = 0;
}
return (res == -INF ? -1 : res);
}
void run() {
cin >> n >> m >> q;
rep(i, 0, m) {
int u, v;
cin >> u >> v;
g[v].pb(u);
}
rep(i, 0, N) {
rep(j, 0, K) {
cnt[i] = 0;
best[i][j] = {-INF, -1};
}
}
rep(i, 1, n + 1) {
cnt[i] = 1;
best[i][0] = {0, i};
for (int j : g[i]) {
rep(t, 0, cnt[j]) {
best[j][t].first++;
}
merge(best[i], best[i] + cnt[i], best[j], best[j] + cnt[j], tmp);
rep(t, 0, cnt[j]) {
best[j][t].first--;
}
int tot = cnt[i] + cnt[j];
cnt[i] = min(tot, K);
int id = 1;
per(t, cnt[i] - 1, 0) {
best[i][t] = tmp[tot - id];
id++;
}
}
}
rep(i, 0, q) {
cin >> t[i] >> y[i];
c[i].resize(y[i]);
rep(j, 0, y[i]) {
cin >> c[i][j];
}
if (y[i] >= K) {
ans[i] = naive(i);
} else {
ans[i] = small(i);
}
}
rep(i, 0, q) {
cout << ans[i] << "\n";
}
}
