#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
#define F first
#define S second
const int N = 1e5 + 3, SQ = 520;
int n, m, q, dis[N];
vector<int> radj[N];
queue<int> qu;
bool mark[N];
vector<pair<int, int>> vec[N];
void bfs() {
while(qu.size()) {
int v = qu.front();
mark[v] = false;
qu.pop();
for (auto u : radj[v])
if (dis[v] + 1 > dis[u]) {
dis[u] = dis[v] + 1;
if (!mark[u]) {
qu.push(u);
mark[u] = true;
}
}
}
}
signed main(){
ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
cin >> n >> m >> q;
for (int i = 0; i < m; i++) {
int v, u;
cin >> v >> u;
radj[u].push_back(v);
}
set<pair<int, int>> st;
for (int i = 1; i <= n; i++) {
if (radj[i].size() == 0)
vec[i].push_back({i, 0});
else {
for (auto v : radj[i]) {
for (auto u : vec[v]) {
if (dis[u.F] == 0) {
dis[u.F] = u.S + 1;
st.insert({dis[u.F], u.F});
}
else if(dis[u.F] < u.S + 1) {
st.erase({dis[u.F], u.F});
dis[u.F] = u.S + 1;
st.insert({dis[u.F], u.F});
}
if (st.size() > SQ) {
int f = st.begin()->S;
dis[f] = 0;
st.erase(st.begin());
}
}
}
while (st.size()) {
int v = st.begin()->second, f = st.begin()->first;
st.erase(st.begin());
vec[i].push_back({v, f});
dis[v] = 0;
}
vec[i].push_back({i, 0});
sort(vec[i].begin(), vec[i].end());
}
}
while (q--) {
int t, y;
cin >> t >> y;
int c[y + 1];
c[y] = n + 1;
for (int i = 0; i < y; i++)
cin >> c[i];
if (y <= SQ) {
int p = 0, ans = -1;
for (int i = 0; i < int32_t(vec[t].size()); i++) {
while (c[p] < vec[t][i].F)
p++;
if (vec[t][i].F != c[p])
ans = max(vec[t][i].S, ans);
}
cout << ans << endl;
}
else {
qu.push(t);
bfs();
int p = 0, ans = -1;
for (int i = 1; i <= t; i++) {
while (c[p] < i)
p++;
if (i != c[p])
ans = max(ans, dis[i]);
dis[i] = 0;
}
cout << ans << endl;
}
}
}
