// oooo
/*
har chi delet mikhad bebar ~
gitar o ba khodet nabar! ~
;Amoo_Hasan;
*/
#include<bits/stdc++.h>
//#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")
using namespace std;
typedef long long ll;
typedef long double ld;
#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl
#define endl '\n'
constexpr ll inf = 1e18, N = 1e5 + 10, SQ = 340;
int n, m, q, ans_t[N];
int t[N], y[N];
pair<int, int> dp[N][SQ];
bool mark[N], ex[N];
vector<int> adj[N], radj[N], vc[N], topol;
void dfs(int x) {
mark[x] = 1;
for(auto j : adj[x]) {
if(mark[j]) continue;
dfs(j);
}
topol.push_back(x);
}
int main() {
ios :: sync_with_stdio(0), cin.tie(0);
cin >>n >>m >>q;
for(int i = 0; i < m; i++) {
int u, v; cin >>u >>v;
adj[u].push_back(v);
radj[v].push_back(u);
}
for(int i = 1; i <= n; i++) {
if(!mark[i]) dfs(i);
}
reverse(All(topol));
for(int i = 0; i < q; i++) {
cin >>t[i] >>y[i];
if(y[i] >= SQ) {
vector<int> his;
for(int j = 0; j < y[i]; j++) {
int u; cin >>u;
his.push_back(u);
ex[u] = 1;
}
int ans = -1;
memset(mark, 0, sizeof(mark));
priority_queue<pair<int, int> > pq; pq.push({0, t[i]});
while(!pq.empty()) {
int p = pq.top().second, q = pq.top().first; pq.pop();
mark[p] = 1;
if(!ex[p]) ans = max(ans, q);
for(auto j : radj[p]) {
if(mark[j]) continue;
pq.push({q + 1, j});
}
}
for(auto j : his) {
ex[j] = 0;
}
his.clear();
ans_t[i] = ans;
continue;
}
for(int j = 0; j < y[i]; j++) {
int u; cin >>u;
vc[i].push_back(u);
}
}
memset(dp, -1, sizeof(dp));
for(auto u : topol) {
int ptr = 0;
priority_queue<pair<pair<int, int>, pair<int, int> > > pq;
for(auto v : radj[u]) {
pq.push({dp[v][0], {0, v}});
}
memset(mark, 0, sizeof(mark));
while(!pq.empty() && ptr < SQ) {
int v = pq.top().second.second, ptrv = pq.top().second.first; pair<int, int> val = pq.top().first; pq.pop();
if(val.first == -1) break;
if(!mark[val.second])
dp[u][ptr++] = {val.first + 1, val.second};
mark[val.second] = 1;
pq.push({dp[v][++ptrv], {ptrv, v}});
}
if(ptr < SQ) dp[u][ptr] = {0, u};
}
/*cout<<"------------" <<endl;
for(auto j : topol) cout<<j <<' ';
cout<<endl;
*/
// cout<<dp[4][1].first <<" " <<dp[4][1].second <<endl;
for(int i = 0; i < q; i++) {
if(y[i] >= SQ) cout<<ans_t[i] <<endl;
else {
bool f = 0;
for(auto j : vc[i]) {
ex[j] = 1;
}
for(int j = 0; j < SQ; j++) {
if(!ex[dp[t[i]][j].second]) {
cout<<dp[t[i]][j].first <<endl;
f = 1;
break;
}
}
if(!f) {
cout<<-1 <<endl;
}
for(auto j : vc[i]) {
ex[j] = 0;
}
}
}
return 0;
}
