#include <bits/stdc++.h>
#define DEBUG false
using namespace std;
const int N = 1e5+10, BS = 200, INF = 1e9;
using pi = pair<int,int>;
int n,m,Q, sz[N], dis[N][BS], node[N][BS], tv[BS], tn[BS];
vector<int> bl, G[N];
bool ban[N];
void preprocess(){
for(int u = 1; u <= n; u++){
if(sz[u] < BS){
dis[u][sz[u]] = 0;
node[u][sz[u]] = u;
sz[u]++;
}
for(int v : G[u]){ //propagate current max to its child
int i = 0, j = 0, k = 0; //perform alike merge sort
while(i < sz[u] and j < sz[v] and k < BS){
if(dis[u][i] + 1 > dis[v][j]){
if(!ban[node[u][i]]){
tv[k] = dis[u][i] + 1;
tn[k] = node[u][i];
ban[node[u][i]] = true;
k++;
}
i++;
} else {
if(!ban[node[v][j]]){
tv[k] = dis[v][j];
tn[k] = node[v][j];
ban[node[v][j]] = true;
k++;
}
j++;
}
}
while(i < sz[u] and k < BS){
if(!ban[node[u][i]]){
tv[k] = dis[u][i] + 1;
tn[k] = node[u][i];
ban[node[u][i]] = true;
k++;
}
i++;
}
while(j < sz[v] and k < BS){
if(!ban[node[v][j]]){
tv[k] = dis[v][j];
tn[k] = node[v][j];
ban[node[v][j]] = true;
k++;
}
j++;
}
for(int l = 0; l < k; l++){
dis[v][l] = tv[l];
node[v][l] = tn[l];
ban[tn[l]] = false;
}
sz[v] = k;
}
}
return;
}
int main(void){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> m >> Q;
for(int i = 1; i <= m; i++){
int u, v; cin >> u >> v;
G[u].emplace_back(v);
}
preprocess();
if(DEBUG){
for(int u = 1; u <= n; u++){
cout << "U : " << u << "\n";
for(int i = 0; i < sz[u]; i++){
cout << dis[u][i] << " " << node[u][i] << "\n";
}
cout << "\n\n";
}
}
while(Q--){
int st, Y; cin >> st >> Y;
bl.resize(Y);
for(int &id : bl){
cin >> id;
ban[id] = true;
}
if(Y >= BS){
int mx[N+5];
for(int i = 1; i <= n; i++) mx[i] = -INF;
for(int i = 1; i <= n; i++){
if(!ban[i]) mx[i] = max(0, mx[i]);
if(mx[i] <= -INF) continue;
for(int v : G[i]){
mx[v] = max(mx[v], mx[i] + 1);
}
}
if(mx[st] <= -INF) cout << "-1\n";
else cout << mx[st] << "\n";
}else{
int ans = -1;
for(int l = 0; l < sz[st]; l++){
int val = dis[st][l], idx = node[st][l];
if(!ban[idx]){
ans = val;
break;
}
}
cout << ans << "\n";
}
for(int id : bl) ban[id] = false;
bl.clear();
}
return 0;
}
