#include "bits/stdc++.h"
using namespace std;
#define int long long
const int maxn = 1e5 + 5;
const int B = 200;
int n, m, q;
vector<int> g[maxn];
vector<pair<int, int>> lp[maxn];
int del[maxn], d[maxn], mx[maxn][2];
void solve() {
cin >> n >> m >> q;
for(int i = 1; i <= m; ++i) {
int u, v; cin >> v >> u;
g[u].push_back(v);
}
memset(mx, 0, sizeof(mx));
for(int i = 1; i <= n; ++i) {
vector<int> cur;
for(auto v:g[i]) {
for(auto j:lp[v]) {
int w = j.first, oe = j.second;
if(mx[oe][1] != i) {
cur.push_back(oe);
mx[oe][1] = i;
mx[oe][0] = w + 1;
}
else {
mx[oe][0] = max(mx[oe][0], w + 1);
}
}
}
for(auto j:cur) {
lp[i].push_back({mx[j][0], j});
}
lp[i].push_back({0, i});
sort(lp[i].begin(), lp[i].end(), greater<pair<int, int>>());
while((int)lp[i].size() > B) {
lp[i].pop_back();
}
}
while(q--) {
int sz, x; cin >> x >> sz;
vector<int> cur;
for(int i = 1; i <= sz; ++i) {
int u; cin >> u;
cur.push_back(u);
del[u] = 1;
}
if(sz >= B) {
for(int i = 0; i <= n; ++i) d[i] = -1;
for(int i = 1; i <= x; ++i) {
if(!del[i]) d[i] = 0;
for(auto u:g[i]) {
if(d[u] != -1) d[i] = max(d[i], d[u] + 1);
}
}
cout << d[x] << '\n';
}
else {
int res = -1;
for(int i = 0; i < (int)lp[x].size(); ++i) {
if(!del[lp[x][i].second]) {
res = lp[x][i].first;
break;
}
}
cout << res << '\n';
}
for(auto &i:cur) del[i] = 0;
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
solve();
return 0;
}
