#include <iostream>
using namespace std;
#include <vector>
#include <algorithm>
#include <cmath>
const int maxn = 1e5 + 3, maxs = 100;
struct Path {
int v, dist;
};
vector<int> g[maxn];
vector<Path> topK[maxn];
bool exist[maxn], invalid[maxn];
int dist[maxn];
void preprocess(int u) {
topK[u] = {{u, 0}};
for (int &v : g[u]) {
auto a = topK[u], b = topK[v];
for (auto &path : a) exist[path.v] = false;
for (auto &path : b) exist[path.v] = false;
topK[u].resize(0);
while (topK[u].size() < maxs + 3) {
Path curA = {-1, 0}, curB = {-1, -1};
while (a.size() && exist[a.back().v]) a.pop_back();
while (b.size() && exist[b.back().v]) b.pop_back();
if (a.size()) curA = a.back();
if (b.size()) curB = b.back();
if (curA.dist < ++curB.dist) swap(curA, curB);
if (curA.v < 0) break;
topK[u].push_back(curA);
exist[curA.v] = true;
}
reverse(begin(topK[u]), end(topK[u]));
}
}
int maxDist(int u) {
int res = -1;
dist[u] = 0;
for (int i = u; i; --i) for (int &v : g[i]) {
dist[v] = dist[i] + 1;
if (!invalid[v]) {
res = max(res, dist[v]);
}
}
return res;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
static char buf[1 << 20];
cout.rdbuf() -> pubsetbuf(buf, sizeof(buf));
int n, m, q; cin >> n >> m >> q;
while (m--) {
int u, v; cin >> u >> v;
if (u < v) swap(u, v);
g[u].push_back(v);
}
for (int i = 1; i <= n; ++i) preprocess(i);
for (auto &u : topK) reverse(begin(u), end(u));
while (q--) {
int t, y; cin >> t >> y;
vector<int> c(y);
for (int &u : c) {
cin >> u;
invalid[u] = true;
}
if (y < maxs) for (auto &cur : topK[t]) {
if (!invalid[cur.v]) {
cout << cur.dist << '\n';
goto skip;
}
} else {
cout << maxDist(t) << '\n';
goto skip;
}
cout << -1 << '\n';
skip: true;
for (int &u : c) {
invalid[u] = false;
}
}
}
