#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int NMAX = 1e5;
const int BSIZE = 316;
int n, m, q;
int v[NMAX + 1];
int dp[NMAX + 1];
vector<int> g[NMAX + 1], gt[NMAX + 1];
pair<int, int> best[NMAX + 1][BSIZE + 1];
pair<int, int> c[2 * BSIZE + 1];
int solve_heavy(int t, int k) {
fill(dp + 1, dp + t + 1, 0);
for(int i = 1; i <= k; i++) {
dp[v[i]] = -1;
}
for(int i = 1; i <= t; i++) {
for(int j : gt[i]) {
if(dp[j] != -1) {
dp[i] = max(dp[i], dp[j] + 1);
}
}
}
return dp[t];
}
int solve_light(int t, int k) {
unordered_set<int> s;
for(int i = 1; i <= k; i++) {
s.insert(v[i]);
}
for(int i = 1; i <= BSIZE; i++) {
if(!s.count(best[t][i].second)) {
return best[t][i].first;
}
}
return -1;
}
void combine(pair<int, int> a[], pair<int, int> b[]) {
int i = 1, j = 1, ind = 0;
while(i <= BSIZE && j <= BSIZE) {
if(b[j].first == -1) {
j++;
}
else if(a[i].first > b[j].first + 1) {
c[++ind] = a[i++];
}
else {
c[++ind] = {b[j].first + 1, b[j].second};
j++;
}
}
while(i <= BSIZE) {
c[++ind] = a[i++];
}
while(j <= BSIZE) {
c[++ind] = {b[j].first + 1, b[j].second};
j++;
}
unordered_set<int> s;
ind = 0;
for(int i = 1; i <= 2 * BSIZE; i++) {
if(!s.count(c[i].second)) {
c[++ind] = c[i];
s.insert(c[i].second);
}
}
for(int i = 1; i <= BSIZE; i++) {
a[i] = (i <= ind ? c[i] : make_pair(-1, 0));
}
}
void precompute() {
for(int i = 1; i <= n; i++) {
fill(best[i] + 1, best[i] + BSIZE + 1, make_pair(-1, 0));
best[i][1] = {0, i};
for(int j : gt[i]) {
combine(best[i], best[j]);
}
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n >> m >> q;
for(int i = 1; i <= m; i++) {
int a, b;
cin >> a >> b;
g[a].push_back(b);
gt[b].push_back(a);
}
precompute();
while(q--) {
int t, k;
cin >> t >> k;
for(int i = 1; i <= k; i++) {
cin >> v[i];
}
if(k > BSIZE) {
cout << solve_heavy(t, k) << '\n';
}
else {
cout << solve_light(t, k) << '\n';
}
}
return 0;
}
