#include <bits/stdc++.h>
using namespace std;
#define maxn 100010
#define endl '\n'
const int block = 300;
const int inf = 1234567890;
int bestval[maxn][block]; //all 0's is good
int bestdist[maxn][block]; //starts at all 0's which is good
int ndist[block];
int nval[block];
int bd[maxn]; //used for things that are greater than square root n
int bv[maxn];
bool cseen[maxn]; //used during the merge thing
bool illegal[maxn]; //used for queries greater than maxn
int N, M, Q;
vector<vector<int>> adj(maxn);
void merge(int x, int y) {
// cout << "merging: " << x << " into " << y << endl;
//merge everything from y into x (going to y will increase distance by 1)
int ind = -1;
int p1 = 0;
int p2 = 0;
while (++ind < block) { //run a merge-sort like algorithm
// cout << ind << " - " << block << endl;
cseen[0] = false;
while (cseen[bestval[x][p1]]) ++p1;
while (cseen[bestval[y][p2]]) ++p2;
if (bestdist[x][p1] > bestdist[y][p2]+1) {
ndist[ind] = bestdist[x][p1];
nval[ind] = bestval[x][p1];
p1++;
cseen[nval[ind]] = true;
}
else {
ndist[ind] = bestdist[y][p2]+1;
nval[ind] = bestval[y][p2];
p2++;
cseen[nval[ind]] = true;
}
}
for (int i = 0; i < block; i++) {
bestval[x][i] = nval[i];
bestdist[x][i] = ndist[i];
cseen[nval[i]] = false; //unmark it for the next iteration
}
}
void recalculate() {
for (int i = 1; i <= N; i++) {
bd[i] = 0;
if (!illegal[i]) {
bv[i] = i;
}
else {
bv[i] = 0;
bd[i] = -inf;
}
for (int val : adj[i]) {
if (bd[val] + 1 > bd[i]) {
bd[i] = bd[val]+1;
bv[i] = bv[val]; //don't think i actually need this but maybe
}
}
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> N >> M >> Q;
int ti; //party location in the query
int yi; //used for queries
int s, e; //used for edges
for (int i = 0; i < M; i++) {
cin >> s >> e; //reverse edges here
adj[e].push_back(s);
}
//process from back to front
for (int i = 1; i <= N; i++) {
// cout << "at: " << i << endl;
//want what can get to this (or what this gets to in reversed graph)
fill(bestdist[i], bestdist[i]+block, -inf);
//calculate everything for this
bestval[i][0] = i; //store myself
bestdist[i][0] = 0;
for (int val : adj[i]) {
merge(i, val);
}
// cout << "best dist for " << i << ": " << bestdist[i][0] << endl;
}
int cur;
while (Q--) {
// cout << "here: " << Q << endl;
cin >> ti >> yi;
vector<int> cl; //current illegal
for (int i = 0; i < yi; i++) {
cin >> cur;
cl.push_back(cur);
illegal[cur] = true;
}
//do processing
if (yi < block) {
//do first thing
int ind = 0;
while (illegal[bestval[ti][ind]]) {
// cout << ind << ": " << bestval[ti][ind] << endl;
ind++;
}
// cout << ind << ": " << bestval[ti][ind] << endl;
if (bestval[ti][ind] != 0 && bestdist[ti][ind] >= 0) {
cout << bestdist[ti][ind] << endl;
}
else cout << -1 << endl;
}
else {
recalculate();
if (bv[ti] != 0 && bd[ti] >= 0) {
cout << bd[ti] << endl;
//we just want the distance, not the index
}
else cout << -1 << endl;
}
//mark the things as ok again
for (int i = 0; i < yi; i++) {
illegal[cl[i]] = false;
}
}
cout.flush();
cin >> N;
}
