#include <bits/stdc++.h>
using namespace std;
#define MAXN 450
#define UPPER 100003
#define pii array<int,2>
int val[UPPER], dp[UPPER];
vector<int> g[UPPER], bucket[UPPER], rev[UPPER];
vector<pii> pref[UPPER];
bool seen[UPPER], seen1[UPPER];
int MX[UPPER];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
for (int i=0;i<UPPER;i++) {
MX[i] = -1;
}
int n,m,q;cin>>n>>m>>q;
for (int i=0;i<m;i++) {
int a,b;cin>>a>>b;a--;b--;
g[a].push_back(b);
rev[b].push_back(a);
}
// precalc
for (int i=0;i<n;i++) {
vector<int> idx = {i};
MX[i] = 0;
for (int x:rev[i]) {
for (auto y:pref[x]) {
MX[y[0]] = max(MX[y[0]], y[1]+1);
if (!seen1[y[0]]) {
seen1[y[0]] = true;
idx.push_back(y[0]);
}
}
}
// bucket sort
int mx = 0;
for (auto &x:idx) {
mx = max(mx, MX[x]);
bucket[MX[x]].push_back(x);
}
vector<pii> tmp;
int cnt=0;
for (int j=mx;j>=0;j--) {
for (auto x:bucket[j]) {
if (!seen[x]) {
seen[x] = true;
tmp.push_back({x, j});
cnt++;
if (cnt == MAXN) break;
}
}
if (cnt == MAXN) break;
}
for (auto &x:idx) {
bucket[MX[x]].clear();
MX[x] = -1;
seen1[x] = false;
}
pref[i] = tmp;
for (auto x:tmp) {
seen[x[0]]=false;
}
}
for (int i=0;i<q;i++) {
int t,y;cin>>t>>y;
for (int i=0;i<y;i++){cin>>val[i];val[i]--;seen[val[i]]=true;}
t--;
bool found = false;
for (auto x:pref[t]) {
if (!seen[x[0]]) {
cout<<x[1]<<"\n";
found = true;
break;
}
}
if (!found && pref[t].size() >= MAXN) {
for (int i=0;i<n;i++) {
dp[i] = 0;
}
for (int i=0;i<n;i++) {
if (seen[i]) continue;
for (int x:g[i]) {
dp[x] = max(dp[x], dp[i]+1);
}
}
if (dp[t] != 0 || !seen[t]) {
cout<<dp[t]<<"\n";
}
else {
cout<<"-1\n";
}
}
else if (!found) {
cout<<-1<<"\n";
}
for (int i=0;i<y;i++) {
seen[val[i]] = false;
}
}
}
