/* In the name of God, aka Allah */
// let this be mytemp.cpp
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
#define mk make_pair
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int inf = 1e9 + 50;
const int N = 1e5 + 50, SQ = 315;
int n, m, q, pd[N];
bool vis[N];
pii dp[N][SQ], tmp[SQ];
vector<int> adj[N];
void push(int u, int v) {
int p1 = 0, p2 = 0, pt = 0;
while (pt < SQ && p1 < SQ && p2 < SQ) {
if (dp[v][p1].F > dp[u][p2].F) {
if (dp[v][p1].F < 0 || !vis[dp[v][p1].S]) tmp[pt++] = dp[v][p1], vis[dp[v][p1].S] = 1;
p1++;
}
else {
if (dp[u][p2].F < 0 || !vis[dp[u][p2].S]) tmp[pt] = dp[u][p2], tmp[pt].F++, pt++, vis[dp[u][p2].S] = 1;
p2++;
}
}
while (pt < SQ && p1 < SQ) {
if (dp[v][p1].F < 0 || !vis[dp[v][p1].S]) tmp[pt++] = dp[v][p1], vis[dp[v][p1].S] = 1;
p1++;
}
while (pt < SQ && p2 < SQ) {
if (dp[u][p2].F < 0 || !vis[dp[u][p2].S]) tmp[pt] = dp[u][p2], tmp[pt].F++, pt++, vis[dp[u][p2].S] = 1;
p2++;
}
for (int i = 0; i < SQ; i++) {
dp[v][i] = tmp[i];
vis[tmp[i].S] = 0;
}
}
void solve() {
cin >> n >> m >> q;
for (int i = 1; i <= m; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
}
for (int u = 1; u <= n; u++) {
sort(adj[u].begin(), adj[u].end());
adj[u].resize(unique(adj[u].begin(), adj[u].end())-adj[u].begin());
dp[u][0] = {0, u};
for (int i = 1; i < SQ; i++) {
dp[u][i] = {-inf, 0};
}
}
for (int u = 1; u <= n; u++) {
for (int v:adj[u]) {
push(u, v);
}
}
vector<int> vc;
while (q--) {
int x, s;
cin >> x >> s;
vc.clear();
int ans = 0;
for (int i = 1; i <= s; i++) {
int v;
cin >> v;
vc.push_back(v);
}
if (s < SQ) {
for (int u:vc) vis[u] = 1;
for (int i = 0; i < SQ; i++) {
if (vis[dp[x][i].S]) continue;
ans = dp[x][i].F;
break;
}
for (int u:vc) vis[u] = 0;
}
else {
for (int u = 1; u <= n; u++) pd[u] = 0;
for (int u:vc) pd[u] = -inf;
for (int u = 1; u <= n; u++) {
for (int v:adj[u]) {
pd[v] = max(pd[v], pd[u]+1);
}
}
ans = pd[x];
}
cout << (ans < 0? -1 : ans) << endl;
}
}
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
