#include <bits/stdc++.h>
using namespace std;
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
template <typename T>
bool maxi(T& a, T b) {
if (b > a) return a = b, true;
return false;
}
template <typename T>
bool mini(T& a, T b) {
if (b < a) return a = b, true;
return false;
}
string to_string(string s) {
return '"' + s + '"';
}
string to_string(const char* s) {
return to_string((string) s);
}
string to_string(bool b) {
return (b ? "true" : "false");
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
bool first = true;
string res = "{";
for (const auto &x : v) {
if (!first) {
res += ", ";
}
first = false;
res += to_string(x);
}
res += "}";
return res;
}
void debug_out() {
cerr << endl;
}
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << " " << to_string(H);
debug_out(T...);
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
const int N = 1e5 + 5;
const int M = 2e5 + 5;
const int Q = 1e5 + 5;
const int B = 350;
int n, m, q;
vector<int> radj[N];
int t, y;
int c[N];
bool ded[N];
int vis[N];
int len[N]; // len[u] = current length of path starting from u
vector<pair<int, int>> best[N]; // B best paths ends at u
void pre() {
for (int i = 1; i <= n; i++) {
vector<int> uniq;
for (int v : radj[i]) {
for (pair<int, int> p : best[v]) {
int u = p.second, l = p.first;
if (vis[u] != i) {
vis[u] = i;
uniq.push_back(u);
len[u] = l + 1;
} else {
maxi(len[u], l + 1);
}
}
}
uniq.push_back(i);
sort(all(uniq), [&](int u, int v) {
return len[u] > len[v];
});
best[i].resize(min(B, sz(uniq)));
for (int j = 0; j < sz(best[i]); j++) best[i][j] = make_pair(len[uniq[j]], uniq[j]);
debug(i, best[i]);
}
}
void hard() {
int ans = -1;
for (pair<int, int> p : best[t]) {
int u = p.second, l = p.first;
if (!ded[u]) {
ans = l;
break;
}
}
cout << ans << '\n';
}
int f[N];
void easy() {
memset(f, -1, sizeof f);
f[t] = 0;
int ans = -1;
for (int i = t; i >= 1; i--) {
if (f[i] == -1) continue;
if (!ded[i]) maxi(ans, f[i]);
for (int v : radj[i]) {
maxi(f[v], f[i] + 1);
}
}
cout << ans << '\n';
}
void solve() {
cin >> t >> y;
for (int i = 1; i <= y; i++) {
cin >> c[i];
ded[c[i]] = 1;
}
if (y > B) easy();
else hard();
}
void clean() {
for (int i = 1; i <= y; i++) {
ded[c[i]] = 0;
}
}
signed main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int s, e;
cin >> s >> e;
radj[e].push_back(s);
}
pre();
while (q--) {
solve();
clean();
}
}
/*
https://oj.uz/problem/view/JOI18_bitaro
*/
