/*
ID: varunra2
LANG: C++
TASK: bitaro
*/
#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif
#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e9
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second
const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;
#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions
// int ops = 0;
const int block = 320;
int n, m, q;
vector<bool> vis;
VVI adj;
vector<VII> vals;
void flip(vector<bool>& vis, VI& pos) { trav(x, pos) vis[x] = !vis[x]; }
VII comb(VI& inds, int pos) {
// the size of each vector is <= block
int siz = sz(inds);
if (siz == 0) {
return {MP(0, pos)};
}
priority_queue<pair<PII, int>> pq;
VI ind(siz, 0);
VII ret;
VI use;
for (int i = 0; i < siz; i++) {
pq.push(MP(vals[inds[i]][0], i));
}
int cnt = 0;
while (sz(ret) < block) {
// ops++;
auto x = pq.top();
pq.pop();
if (!vis[x.x.y]) {
vis[x.x.y] = true;
use.PB(x.x.y);
ret.PB(MP(x.x.x + 1, x.x.y));
}
ind[x.y]++;
if (ind[x.y] < sz(vals[inds[x.y]])) {
pq.push(MP(vals[inds[x.y]][ind[x.y]], x.y));
} else if (ind[x.y] == sz(vals[inds[x.y]]))
cnt++;
if (cnt == siz) break;
}
flip(vis, use);
ret.PB(MP(0, pos));
return ret;
}
void init() {
adj.resize(n);
vals.resize(n);
vis.assign(n, false);
}
void gen(int u) { vals[u] = comb(adj[u], u); }
void preprocess() {
for (int i = 0; i < n; i++) {
gen(i);
}
}
void stupid(VI& dist) {
for (int i = n - 1; ~i; i--) {
if (dist[i] == -1) continue;
for (auto& x : adj[i]) dist[x] = max(dist[x], dist[i] + 1);
}
}
int main() {
// #ifndef ONLINE_JUDGE
// freopen("bitaro.in", "r", stdin);
// freopen("bitaro.out", "w", stdout);
// #endif
cin.sync_with_stdio(0);
cin.tie(0);
cin >> n >> m >> q;
init();
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
u--, v--;
adj[v].PB(u);
}
bool calc = false;
vector<bool> vis1(n, false);
while (q--) {
int u, cnt;
cin >> u >> cnt;
u--;
VI bad;
for (int i = 0; i < cnt; i++) {
int v;
cin >> v;
v--;
bad.PB(v);
}
flip(vis1, bad);
if (cnt < block - 1) {
if (!calc) {
calc = true;
preprocess();
}
int ret = -1;
for (int i = 0; i < sz(vals[u]); i++) {
if (!vis1[vals[u][i].y]) {
ret = vals[u][i].x;
break;
}
}
cout << ret << '\n';
} else {
VI dist(n, -1);
dist[u] = 0;
stupid(dist);
int ret = -1;
for (int i = 0; i < n; i++) {
if (vis1[i]) continue;
ret = max(ret, dist[i]);
}
cout << ret << '\n';
}
flip(vis1, bad);
}
// debug(ops);
return 0;
}
