#include <bits/stdc++.h>
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define endl '\n'
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const int INF = 0x3f3f3f3f;
const ll INFLL = 0x3f3f3f3f3f3f3f3fLL;
const int MOD = 1000000007;
const int dx[] = { 0, 0, -1, 1, 1, -1, 1, -1};
const int dy[] = {-1, 1, 0, 0, 1, -1, -1, 1};
const int MAXN = 100010;
const int SQRT = 320;
vector<pair<int, vector<int>>> queries[MAXN];
vector<int> adj[MAXN];
vector<pii> dist[MAXN];
int used1[MAXN], used2[MAXN];
void precompute(int u){
vector<pii> aux;
aux.emplace_back(0, u);
dist[u].assign(SQRT, pii(0, u));
for(int to: adj[u]){
for(pii p: dist[to]){
p.F++;
aux.push_back(p);
}
}
sort(all(aux), greater<pii>());
int i = 0;
for(auto p: aux){
if(used1[p.S] < u){
dist[u][i++] = p;
used1[p.S] = u;
if(i == SQRT)
break;
}
}
}
int dp[MAXN];
bool invalid[MAXN];
int dfs(int u){
if(dp[u] != -1)
return dp[u];
int res = invalid[u] ? -INF : 0;
for(int to: adj[u])
res = max(res, dfs(to) + 1);
return dp[u] = res;
}
int T;
int solve(int u, vector<int> &v){
int ans = -1;
if(v.size() < SQRT){
T++;
for(int to: v){
used2[to] = T;
}
for(auto [d, to]: dist[u]){
if(used2[to] < T){
ans = d;
break;
}
}
}else{
memset(dp, -1, sizeof(dp));
memset(invalid, 0, sizeof(invalid));
for(int to: v)
invalid[to] = true;
ans = max(-1, dfs(u));
}
return ans;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int n, m, q;
cin >> n >> m >> q;
for(int i=0; i<m; i++){
int a, b;
cin >> a >> b;
adj[b].push_back(a);
}
for(int i=1; i<=n; i++)
precompute(i);
for(int i=0; i<q; i++){
int t, y;
cin >> t >> y;
vector<int> v(y);
for(int j=0; j<y; j++)
cin >> v[j];
cout << solve(t, v) << endl;
}
return 0;
}
