#include <iostream>
#include <vector>
#include <set>
#include <queue>
#include <utility>
#include <algorithm>
using namespace std;
using pp=pair<int, int>;
const int maxn = int(1e5) + 10;
const int B = 300;
int n, m, q;
vector<int> re[maxn];
vector<pp> prec[maxn];
int seen[maxn];
int nt;
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m >> q;
for (int i=1; i<=m; ++i) {
int s, e; cin >> s >> e;
re[e].push_back(s);
}
for (int i=1; i<=n; ++i) {
prec[i].reserve(B);
prec[i].push_back({0, i});
for (int j:re[i]) {
vector<pp> tmp, &v1 = prec[i], &v2 = prec[j];
int i1 = 0, i2 = 0;
int s1 = int(v1.size()), s2 = int(v2.size());
++nt;
while (int(tmp.size()) < B && (i1 < s1 || i2 < s2)) {
if (i1 < s1 && (i2 == s2 || v1[i1].first >= v2[i2].first+1)) {
if (seen[v1[i1].second] != nt) {
tmp.push_back(v1[i1]);
}
++i1;
} else {
if (seen[v2[i2].second] != nt) {
tmp.push_back(v2[i2]);
++tmp.back().first;
}
++i2;
}
seen[tmp.back().second] = nt;
}
swap(v1, tmp);
}
}
for (;q--;) {
int dest, igs; cin >> dest >> igs;
static int ign[maxn];
++nt;
for (int i=0; i<igs; ++i) {
cin >> ign[i];
seen[ign[i]] = nt;
}
if (igs < B) {
bool found = 0;
for (auto [dist, from]:prec[dest]) {
if (seen[from] != nt) {
cout << dist << '\n';
found = 1;
break;
}
}
if (!found) {
cout << "-1\n";
}
continue;
}
static int qd[maxn];
fill(qd+1, qd+dest+1, -1);
int ans = -1;
qd[dest] = 0;
for (int i=dest; 1<=i; --i) if (qd[i] != -1) {
if (seen[i] != nt) {
ans = max(ans, qd[i]);
}
for (int j:re[i]) {
qd[j] = max(qd[j], qd[i]+1);
}
}
cout << ans << '\n';
}
return 0;
}
