#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
const int mxN = 1e5 + 2;
const int mxB = 100;
vector<pair<int, int>> path[mxN];
vector<int> radj[mxN];
int mn[mxN], vis[mxN];
signed main(){
ios::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
int n, m, q;
cin >> n >> m >> q;
for(int i = 0; i < n; ++i){
mn[i] = -1, vis[i] = 0;
}
for(int i = 0, u, v; i < m; ++i){
cin >> u >> v; --u, --v;
radj[v].push_back(u);
}
for(int i = 0; i < n; ++i){
path[i].push_back({i, 0});
vector<int> all_node;
for(auto it : radj[i]){
for(auto [v, w] : path[it]){
if(mn[v] == -1){
all_node.push_back(v);
mn[v] = w + 1;
}else if(mn[v] < w + 1){
mn[v] = w + 1;
}
}
}
for(auto it : all_node){
path[i].push_back({it, mn[it]});
}
sort(all(path[i]), [&](pair<int, int> p1, pair<int, int> p2){
return p1.second > p2.second;
});
while(path[i].size() > mxB) path[i].pop_back();
for(auto it : all_node) mn[it] = -1;
}
while(q--){
int x, y;
cin >> x >> y;
--x;
vector<int> ban;
for(int j = 0; j < n; ++j) vis[j] = 0;
while(y--){
int u;
cin >> u;
--u;
vis[u] = 1;
ban.push_back(u);
}
int ans = -1;
if((int) ban.size() >= (int) path[x].size()){
vector<int> dp(x + 1, -1);
dp[x] = 0;
for(int i = x; i >= 0; --i){
if(dp[i] == -1) continue;
if(!vis[i]) ans = max(ans, dp[i]);
for(auto it : radj[i]){
dp[it] = max(dp[it], dp[i] + 1);
}
}
cout << ans << "\n";
}else{
for(auto [u, w] : path[x]){
if(vis[u] == 0){
ans = max(ans, w);
}
}
cout << ans << "\n";
}
for(auto it : ban) vis[it] = 0;
}
return 0;
}
