#include<bits/stdc++.h>
using namespace std;
#define blsiz 200
#define N 100005
#define fi first
#define se second
#define oo 1e9
typedef pair<int, int> ii;
int n, m, q, dep[N], bl[N], val[N], dp[N];
vector<int> adj[N];
vector<ii> pth[N];
vector<int> tmp;
bool cmp(ii& a, ii& b){
return a.fi > b.fi;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cin >> n >> m >> q;
for (int i = 1; i <= m; i++){
int u, v;
cin >> u >> v;
adj[v].push_back(u);
}
for (int i = 1; i <= n; i++) dep[i] = -1;
for (int i = 1; i <= n; i++){
pth[i].push_back({0, i});
tmp.push_back(i);
dep[i] = 0;
for (auto x : adj[i]){
for (auto v : pth[x]){
if (dep[v.se] == -1){
dep[v.se] = v.fi + 1;
tmp.push_back(v.se);
}
else{
dep[v.se] = max(dep[v.se], v.fi + 1);
}
}
}
for (auto x : tmp) { pth[i].push_back({dep[x], x}); dep[x] = -1;}
tmp.clear();
sort(pth[i].begin(), pth[i].end(), cmp);
while ((int) pth[i].size() > blsiz) pth[i].pop_back();
}
for (int i = 1; i <= n; i++) dp[i] = -oo;
while (q--){
int u, sl;
cin >> u >> sl;
for (int i = 1; i <= sl; i++){
cin >> val[i];
bl[val[i]] = 1;
}
if (sl < blsiz){
int res = -1;
for (auto x : pth[u]){
if (!bl[x.se]) res = max(res, x.fi);
}
cout << res << "\n";
for (int i = 1; i <= sl; i++) bl[val[i]] = 0;
continue;
}
int res = -1;
dp[u] = 0;
for (int i = u; i >= 1; i--){
for (auto x : adj[i]){
dp[x] = max(dp[x], dp[i] + 1);
}
if (!bl[i]) res = max(res, dp[i]);
}
cout << res << "\n";
for (int i = 1; i <= sl; i++) bl[val[i]] = 0;
for (int i = 1; i <= u; i++) dp[i] = -oo;
}
return 0;
}
