#include<iostream>
#include<vector>
#include<unordered_map>
#include<algorithm>
#define fi first
#define se second
using namespace std;
using pii = pair<int,int>;
constexpr int nmax = 1e5 + 10;
const int lim = 317;
vector<pii> dp[nmax];
vector<int> g[nmax]; bool nah[nmax];
void merge(int t, int s){
auto cs = dp[s];
for(auto &it : cs)
++it.fi;
vector<pii> rez; int i = 0, j = 0;
while(i < dp[t].size() && j < cs.size()){
if(dp[t][i] > cs[j])
rez.push_back(dp[t][i++]);
else rez.push_back(cs[j++]);
}
while(i < dp[t].size()) rez.push_back(dp[t][i++]);
while(j < cs.size()) rez.push_back(cs[j++]);
dp[t].clear();
for(auto &it : rez){
if(!nah[it.se])
dp[t].push_back(it);
nah[it.se] = 1;
}
for(auto &it : dp[t])
nah[it.se] = 0;
if(dp[t].size() > lim + 1)
dp[t].resize(lim + 1); ///very important
}
int ask(int i){
for(auto &it : dp[i])
if(!nah[it.se])
return it.fi;
return -1;
}
int brut(int i){
vector<int> dp(nmax, -1e9);
for(int j = 1; j <= i; j++){
if(!nah[j]) dp[j] = 0;
for(auto &it : g[j])
dp[j] = max(dp[j], dp[it] + 1);
}
if(dp[i] < 0)
return -1;
return dp[i];
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr), cout.tie(nullptr);
int n, m, q, a, b, t; cin >> n >> m >> q;
for(int i = 0; i < m; i++){
cin >> a >> b;
g[b].push_back(a);
}
for(int i = 1; i <= n ; i++){
dp[i] = {{0, i}};
for(auto &j : g[i])
merge(i, j);
}
for(int i = 0; i < q; i++){
cin >> t >> a; vector<int> block;
for(int _ = 0; _ < a; _++){
cin >> b; nah[b] = 1;
block.push_back(b);
}
if(a <= lim) cout << ask(t) << '\n';
else cout << brut(t) << '\n';
for(auto &it : block)
nah[it] = 0;
}
}
