#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <cctype>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <vector>
#include <cstdlib>
#include <bitset>
#include <deque>
#define inf 0x3f3f3f3f
#define infll 0x3f3f3f3f3f3f3f3fll
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 100005;
vector<int> g[maxn];
vector<pair<int, int> > path[maxn];
int n, m, q;
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int x, y;
cin >> x >> y;
g[y].push_back(x);
}
int B = min((int)sqrt(n + 1), 300);
vector<int> dis(n + 1, 0);
for (int u = 1; u <= n; u++) {
path[u].push_back(make_pair(0, u));
vector<int> port;
for (int v : g[u]) {
for (auto [w, k] : path[v]) {
if (!dis[k]) {
dis[k] = -w + 1;
port.push_back(k);
} else {
dis[k] = max(-w + 1, dis[k]);
}
}
}
for (int v : port) {
path[u].push_back(make_pair(-dis[v], v));
dis[v] = 0;
}
sort(path[u].begin(), path[u].end());
while (path[u].size() > B) path[u].pop_back();
// cout << path[u].size() << endl;
}
vector<int> cut(n + 1, 0);
while (q--) {
int x, y;
cin >> x >> y;
vector<int> c(y + 1, 0);
for (int i = 1; i <= y; i++) {
cin >> c[i];
cut[c[i]] = 1;
}
if (y >= B) {
int ans = -1;
vector<int> f(n + 1, 0);
for (int u = x; u; u--) {
if (u != x && !f[u]) continue;
if (!cut[u]) ans = max(ans, f[u]);
for (int v : g[u]) f[v] = max(f[v], f[u] + 1);
}
cout << ans << "\n";
// cout << "!1\n";
} else {
int ans = -1;
for (auto [w, v] : path[x]) {
// cout << x << " " << v << " " << -w << endl;
if (!cut[v]) {
ans = -w;
break;
}
}
cout << ans << "\n";
// cout << "!2\n";
}
for (int i = 1; i <= y; i++) cut[c[i]] = 0;
}
return 0;
}
