// ~Be name khoda~ //
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define mp make_pair
#define all(x) x.begin(), x.end()
#define fi first
#define se second
#define cl clear
#define endll '\n'
const int maxn = 1e6 + 10;
const int maxn5 = 2e5 + 10;
const int maxnt = 1.2e6 + 10;
const int maxn3 = 1e3 + 10;
const int mod = 1e9 + 7;
const int ssq = 1000;
const ll inf = 2e18;
vector <pair<int, int>> mx[maxn5], big, tmp;
int h[maxn5], ans[maxn5];
vector <int> adj[maxn5], jda[maxn5];
vector <int> tp, req[maxn5];
bool mark[maxn5];
inline bool cmp(pair<int, int> a, pair<int, int> b){return a.se > b.se;}
inline void join(int v, int u){
tmp.clear();
for(auto p : mx[v])
tmp.pb(p);
for(auto p : mx[u])
tmp.pb({p.fi, p.se + 1});
sort(all(tmp), cmp);
while(tmp.size() > ssq + 1)
tmp.pop_back();
/*
int iv = 0, iu = 0;
while(tmp.size() <= ssq && (iv < mx[v].size() || iu < mx[u].size())){
if(iv < mx[v].size() && (iu == mx[u].size() || mx[v][iv].se >= mx[u][iu].se + 1)){
tmp.pb(mx[v][iv]);
iv++;
}
else{
tmp.pb({mx[u][iu].fi, mx[u][iu].se + 1});
iu++;
}
}
*/
mx[v].clear();
for(auto p : tmp)
mx[v].pb(p);
return;
}
inline void dfs(int v){
mark[v] = true;
for(auto u : adj[v]) if(!mark[u])
dfs(u);
tp.pb(v);
return;
}
int main()
{
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
int n, m, q; cin >> n >> m >> q;
for(int i = 0; i < m; i++){
int a, b; cin >> a >> b;
a--; b--;
adj[a].pb(b);
jda[b].pb(a);
}
for(int i = 0; i < n; i++) if(!mark[i])
dfs(i);
fill(mark, mark + n + 5, false);
reverse(all(tp));
for(auto u : tp){
mx[u].pb({u, 0});
for(auto v : jda[u]){
join(u, v);
}
}
memset(ans, -1, sizeof ans);
for(int i = 0; i < q; i++){
int v, k; cin >> v >> k;
v--;
for(int j = 0; j < k; j++){
int a; cin >> a;
a--;
req[i].pb(a);
if(k < ssq)
mark[a] = true;
}
if(k >= ssq){
big.pb({i, v});
}
else{
for(auto [u, h] : mx[v]) if(!mark[u]){
ans[i] = h;
break;
}
for(auto u : req[i])
mark[u] = false;
}
}
for(auto [id, v] : big){
memset(h, -1, sizeof h);
fill(mark, mark + n + 5, false);
for(auto u : req[id])
mark[u] = true;
for(auto u : tp){
if(!mark[u])
h[u] = 0;
for(auto z : jda[u]) if(h[z] > -1)
h[u] = max(h[u], h[z] + 1);
}
ans[id] = h[v];
}
for(int i = 0; i < q; i++)
cout << ans[i] << '\n';
}
