// vaziat meshki-ghermeze !
#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
using namespace std;
typedef pair<int, int> pii;
const int N = 1e5 + 10;
const int Sqrt = 330;
pii mx[N][Sqrt];
pii tmp[Sqrt];
vector<int> I[N], O[N];
int n, m, Q;
int mk[N], T = 0;
int dp[N];
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
for(int i = 0; i < N; i++)
fill(mx[i], mx[i] + Sqrt, pii(-1, -1));
cin >> n >> m >> Q;
int u, v;
for(int i = 0; i < m; i++){
cin >> u >> v;
O[u].pb(v);
I[v].pb(u);
}
for(int i = 1; i <= n; i++){
mx[i][0] = pii(0, i);
for(auto adj : I[i]){
int po = 0, p1 = 0, p2 = 0;
T ++;
while(po < Sqrt){
if(mx[adj][p1].S != -1 && mk[mx[adj][p1].S] == T){
p1 ++;
continue;
}
if(mx[i][p2].S != -1 && mk[mx[i][p2].S] == T){
p2 ++;
continue;
}
if(mx[adj][p1].F + 1 > mx[i][p2].F){
tmp[po ++] = pii(mx[adj][p1].F + (mx[adj][p1].F != -1), mx[adj][p1].S);
// if(tmp[po - 1].S != -1)
// cerr << tmp[po - 1].S << '\n';
p1 ++;
} else {
tmp[po ++] = mx[i][p2];
p2 ++;
}
if(tmp[po - 1].S != -1)
mk[tmp[po - 1].S] = T;
}
memcpy(mx[i], tmp, sizeof tmp);
}
// cerr << i << " -> ";
// for(int k = 0; k < Sqrt; k++){
// if(mx[i][k].S != -1)
// cerr << "( " << mx[i][k].F << ' ' << mx[i][k].S << " ), ";
// }
// cerr << '\n';
}
int sz, pl;
for(int i = 0; i < Q; i++){
cin >> pl >> sz;
T ++;
for(int j = 0; j < sz; j++){
cin >> u;
mk[u] = T;
}
int ans = -1, fl = 0;
for(int j = 0; j < Sqrt; j++){
if(mx[pl][j].S != -1){
if(mk[mx[pl][j].S] != T){
ans = mx[pl][j].F;
break;
}
} else {
fl = 1;
}
}
if(fl){
cout << "-1\n";
continue;
}
if(ans != -1){
cout << ans << '\n';
continue;
}
memset(dp, -1, sizeof dp);
dp[pl] = 0;
int mxx = -1;
for(int i = pl; i > 0; i--){
for(auto adj : O[i])
if(dp[adj] != -1)
dp[i] = max(dp[i], dp[adj] + 1);
if(mk[i] != T)
mxx = max(mxx, dp[i]);
}
cout << mxx << '\n';
}
return 0;
}
