//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#define ll long long
#define maxn 100005
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
const int siz = 320;
vector<int> adj[maxn], from[maxn];
pii pnt[maxn][siz + 3];
pii tmp[siz + 3];
int num[maxn];
inline bool cmp (pii a, pii b) {
return a.ss > b.ss;
}
int dp[maxn];
bool part[maxn], found[maxn];
void getdp(int n, int id) {
for (int i = 1;i <= id;i++) dp[i] = 0;
for (int i = 1;i <= id;i++) {
for (int v:adj[i]) {
dp[v] = max(dp[v], (dp[i] == 0 ? (part[i] ? -1 : 0) : dp[i]) + 1);
}
}
}
void merge(int a, int b) {
int n = num[a], m = num[b], ind = 0, c = 0;
for (int i = 0;i < n;i++) {
while (ind < m && pnt[b][ind].ss + 1 > pnt[a][i].ss) {
if (!found[pnt[b][ind].ff]) {
found[pnt[b][ind].ff] = 1;
tmp[c++] = make_pair(pnt[b][ind].ff, pnt[b][ind].ss + 1);
}
ind++;
if (c > siz) break;
}
if (!found[pnt[a][i].ff]) {
found[pnt[a][i].ff] = 1;
tmp[c++] = pnt[a][i];
}
if (c > siz) break;
}
while (ind < m) {
if (!found[pnt[b][ind].ff]) {
found[pnt[b][ind].ff] = 1;
tmp[c++] = make_pair(pnt[b][ind].ff, pnt[b][ind].ss + 1);
}
ind++;
if (c > siz) break;
}
for (int i = 0;i < c;i++) found[tmp[i].ff] = 0;
num[a] = min(siz, c);
for (int i = 0;i < num[a];i++) pnt[a][i] = tmp[i];
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(0);
int n, m, q;
cin >> n >> m >> q;
for (int i = 0;i < m;i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
from[b].push_back(a);
}
for (int i = 1;i <= n;i++) {
num[i] = 1;
pnt[i][0] = make_pair(i, 0);
for (int v:from[i]) {
merge(i, v);
}
}
getdp(n, n);
while (q--) {
int ind, yi;
cin >> ind >> yi;
vector<int> val;
for (int i = 0;i < yi;i++) {
int x;
cin >> x;
if (x <= ind) part[x] = 1, val.push_back(x);
}
if (yi >= siz) {
getdp(n, ind);
if (part[ind] && dp[ind] == 0) cout << -1 << "\n";
else cout << dp[ind] << "\n";
} else {
int ans = -1;
for (int v = 0;v < num[ind];v++) {
if (!part[pnt[ind][v].ff]) ans = max(ans, pnt[ind][v].ss);
}
cout << ans << "\n";
}
for (int i:val) part[i] = 0;
}
}
/*
5 6 3
1 2
2 4
3 4
1 3
3 5
4 5
4 1 1
5 2 2 3
2 3 1 4 5
*/
