#include <bits/stdc++.h>
#define X first
#define Y second
#define MP make_pair
#define ll long long
using namespace std;
const int N = 4e5 + 1, BS = 330;
const ll INF = 1e18;
int n, m, q, dsu[N], used[N], cnt[N], dp[N];
vector< int > g[N];
vector< pair<int, int> > gg[N];
int ptr[N];
void prep(){
cin >> n >> m >> q;
for(int i = 1, x, y;i <= m;i++){
cin >> x >> y;
g[y].push_back(x);
}
for(int i = 1;i <= n;i++){
for(int from: g[i])
ptr[from] = 0;
while(gg[i].size() <= BS + 1){
int mx = -1;
pair<int, int> need = MP(0, 0);
for(int from: g[i]){
while(ptr[from] < gg[from].size() && used[gg[from][ptr[from]].Y] == i)
ptr[from]++;
if(ptr[from] < gg[from].size() && (mx == -1 || need.X < gg[from][ptr[from]].X))
need = gg[from][ptr[from]], mx = from;
}
need.X++;
if(mx == -1)
break;
else
gg[i].push_back(need), used[need.Y] = i, ptr[mx]++;
}
if(gg[i].size() <= BS + 1)
gg[i].push_back(MP(0, i));
}
}
int main () {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
prep();
for(int pos, len, x, T = N + 1;q--;T++){
cin >> pos >> len;
for(int j = 1;j <= len;j++){
cin >> x, used[x] = T;
}
if(len > 300){
for(int i = 1;i <= pos;i++){
dp[i] = 0, cnt[i] = 0;
if(used[i] != T)
cnt[i] = 1;
for(int from: g[i]){
if(dp[from] + 1 > dp[i] && cnt[from])
dp[i] = dp[from] + 1, cnt[i] = cnt[from];
else if(dp[from] + 1 == dp[i] && cnt[from])
cnt[i]++;
}
}
}
else {
dp[pos] = 0, cnt[pos] = 0;
for(pair<int, int> tmp: gg[pos]){
if(used[tmp.Y] == T)
continue;
if(tmp.X > dp[pos])
dp[pos] = tmp.X, cnt[pos] = 1;
else if(tmp.X == dp[pos])
cnt[pos]++;
}
}
cout << (cnt[pos] == 0 ? -1: dp[pos]) << "\n";
}
}
