#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
using pl = pair<ll,ll>;
using pi = pair<int,int>;
using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pair<int,int>>;
using vpl = vector<pair<ll,ll>>;
#define mp make_pair
#define f first
#define s second
#define foru(i,a,b) for(int i = a ; i <= b;i++)
#define ford(i,a,b) for(int i = a ; i >= b;i--)
#define psh push
#define em emplace
#define eb emplace_back
#define pb push_back
#define all(x) (x).begin(),(x).end()
int n , m , q , u , v , t,y;
vi E[100005];
vi backward[100005];
vpi save[100005];
const int BLOCK_SIZE = 500;
bool notok[100005];
int forbid[100005] , dp[100005];
bool vis[100005];
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
// freopen("D:/.vscode/Codeforces/input.txt","r",stdin);
// freopen("D:/.vscode/Codeforces/output.txt","w",stdout);
cin >> n >> m >> q;
foru(i,1,m){
cin >> u >> v;
E[u].eb(v);
backward[v].eb(u);
}
foru(i,1,n){
for(int d : backward[i]){
vpi temp;
save[d].pb({0,d});
int p1 = 0 , p2 = 0 , a = save[d].size() , b= save[i].size();
while(temp.size() < BLOCK_SIZE && (p1 < a || p2 < b)){
if(p2==b || (p1!=a&& save[d][p1].f + 1 >= save[i][p2].f)){
temp.pb({save[d][p1].f+1,save[d][p1].s});
vis[save[d][p1].s] = 1;
p1++;
}
else {
temp.pb(save[i][p2]);
vis[save[i][p2].s] = 1;
p2++;
}
while(p1<a&&vis[save[d][p1].s]) p1++;
while(p2<b&&vis[save[i][p2].s]) p2++;
}
save[d].pop_back();
for(auto x : temp) vis[x.s] = 0;
swap(temp,save[i]);
}
}
foru(i,1,q){
cin >> t >> y;
int ans = -1;
foru(j,1,y){
cin >> forbid[j];
notok[forbid[j]] = 1;
}
if(!notok[t]) ans = 0;
if(y < BLOCK_SIZE){
foru(j,0,(int)save[t].size() - 1){
if(!notok[save[t][j].s]){
ans = max(ans,save[t][j].f);
break;
}
}
}
else {
foru(j,1,n) dp[j] = -1;
dp[t] = 0;
ford(j,t-1,1){
for(int x : E[j]){
if(dp[x] != -1) dp[j] = max(dp[j], dp[x] + 1);
}
if(!notok[j]) ans = max(ans,dp[j]);
}
}
cout << ans << '\n';
foru(j,1,y) notok[forbid[j]] = 0;
}
}
