#include <bits/stdc++.h>
using namespace std;
#define pb push_back
typedef pair <int, int> pii;
const int maxn = 1e5 + 10, maxm = 2e5 + 10, sq = 320;
int n, m, q, size[maxn], h[maxn], input[maxn];
vector <pii> mx[maxn], vec;
vector <int> in[maxn];
bitset <maxn> mark;
bool cmp(const pii &p1, const pii &p2) {
return p1 > p2;
}
int main(){
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cin >> n >> m >> q;
for (int i = 0; i < n; ++i)
mx[i].reserve(sq);
for (int i = 0, v, u; i < m; ++i) {
cin >> v >> u;
in[--u].pb(--v);
}
vec.resize(sq + sq);
for (int i = 0; i < n; ++i) {
mx[i].pb({-1, i});
for (auto j: in[i]) {
int se = mx[i].size(), se2 = mx[j].size();
vec.resize(se + se2);
merge(mx[i].begin(), mx[i].end(), mx[j].begin(), mx[j].end(), vec.begin(), cmp);
if (int(vec.size()) > sq)
vec.resize(sq);
mx[i].swap(vec);
}
size[i] = mx[i].size();
for (int j = 0; j < size[i]; ++j)
mx[i][j].first++;
}
for (int i = 0, v, num; i < q; ++i) {
cin >> v >> num; --v;
for (int j = 0; j < num; ++j) {
cin >> input[j];
mark[--input[j]] = true;
}
int ans = -1;
for (int j = 0; j < size[v]; ++j)
if (!mark[mx[v][j].second]) {
ans = mx[v][j].first;
break;
}
if (ans == -1) {
memset(h, -63, sizeof(h));
h[v] = 0;
for (int j = v; ~j; --j) {
if (!mark[j])
ans = max(ans, h[j]);
for (auto u: in[j])
h[u] = max(h[u], h[j] + 1);
}
}
cout << ans << '\n';
for (int j = 0; j < num; ++j)
mark[input[j]] = false;
}
return 0;
}
