#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;
using vpii = vector<pii>;
using vpll = vector<pll>;
#define endl '\n'
#define pb push_back
#define eb emplace_back
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)(x).size()
#define rep(i, a, b) for (int i = (a); i < (b); ++i)
#define rev(i, a, b) for (int i = (a); i >= (b); --i)
const ll inf = 1e18;
const int mod = 1e9 + 7;
const int maxn = 2e5 + 5;
void fast_io() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
}
vector<bool> vis;
vi d;
vpii dist;
vector<vi> a;
vector<vpii> b;
void solve() {
int n, m, q, u, v;
cin >> n >> m >> q;
a.resize(n + 1);
b.resize(n + 1);
dist.resize(n + 1);
vis.resize(n + 1);
d.resize(n + 1);
int block = 500;
rep(i, 0, m) {
cin >> u >> v;
a[v].pb(u);
}
vi c(n + 1, 0);
rep(i, 1, n + 1) {
rep(j, 0, block) {
pii nd = {0, 0};
int cur = 0;
for(int &k: a[i]) {
while(c[k] < b[k].size() && vis[b[k][c[k]].ss]) c[k]++;
if (c[k] < b[k].size() && b[k][c[k]].ff + 1 > nd.ff && !vis[b[k][c[k]].ss])
nd = {b[k][c[k]].ff + 1, b[k][c[k]].ss}, cur = k;
else if (c[k] == b[k].size() && 1 > nd.ff && !vis[k])
nd = {1, k}, cur = k;
}
// cout << "filling " << i << ' ' << nd.ff << ' ' << nd.ss << endl;
if (nd.ss != 0) b[i].pb(nd), vis[nd.ss] = 1, c[cur]++;
else break;
}
for(int &j: a[i]) c[j] = 0;
rep(j, 0, sz(b[i])) vis[b[i][j].ss] = 0;
}
// rep(i, 1, n + 1) {
// cout << i << " ==== ";
// for (pii &j: b[i]) cout << j.ss << ' ';
// cout << endl;
// }
rep(i, 1, n + 1) dist[i] = {0, i};
while(q--) {
int t, y;
auto clear = [](int y) {
rep(i, 0, y) vis[d[i]] = 0;
};
cin >> t >> y;
rep(i, 0, y) cin >> d[i], vis[d[i]] = 1;
bool flag = 0;
for (pii &i: b[t])
if (!vis[i.ss]) {
cout << i.ff << '\n';
flag = true;
break;
}
if (flag) {clear(y); continue;}
rep(i, 1, n + 1) {
for (int &j: a[i]) {
if (dist[j].ff + 1 > dist[i].ff && !vis[dist[j].ss])
dist[i] = {dist[j].ff + 1, dist[j].ss};
}
}
if (!dist[t].ff && vis[t]) cout << -1 << '\n';
else cout << dist[t].ff << '\n';
rep(i, 1, n + 1) vis[i] = 0, dist[i] = {0, i};
}
}
int main() {
// freopen("file.in", "r", stdin);
// freopen("file.out", "w", stdout);
fast_io();
int t = 1;
while (t--) {
solve();
}
return 0;
}
