/*
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
bool pr = false;
int ops = 0;
const int block = 350;
int n, m, q;
vector<bool> vis;
VI dists;
VVI adj;
vector<VII> vals;
void flip(vector<bool>& vis, VI& pos) { trav(x, pos) vis[x] = !vis[x]; }
priority_queue<pair<PII, int>> pq;
static bool cmp(int& a, int& b) { return dists[a] > dists[b]; }
void gen(int u) {
VI use;
use.PB(u);
for (auto& x : adj[u]) {
for (auto& val : vals[x]) {
if (!dists[val.y]) {
use.PB(val.y);
}
dists[val.y] = max(dists[val.y], val.x + 1);
}
}
nth_element(use.begin(), use.begin() + min(block, sz(use)), use.end(), cmp);
for (int i = 0; i < min(block, sz(use)); i++) {
vals[u].PB(MP(dists[use[i]], use[i]));
}
for (auto& x : use) dists[x] = 0;
}
void init() {
adj.resize(n);
vals.resize(n);
dists.assign(n, 0);
vis.assign(n, false);
}
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;
if (n < 20) pr = true;
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 = max(vals[u][i].x, ret);
}
}
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);
}
// if (pr) trav(x, vals) debug(x);
debug(ops);
return 0;
}
