#include <bits/stdc++.h>
#define int long long
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define last(a) a[sz(a)-1]
using namespace std;
vector<int> memo;
vector<vector<int>> neigh;
vector<vector<int>> neigh2;
vector<int> topo;
vector<int> tin;
vector<int> out;
int timer=0;
int dp(int x){
if(memo[x]>-1) return memo[x];
memo[x]=0;
for (auto u : neigh[x]) memo[x]=max(memo[x],dp(u)+1);
topo.push_back(memo[x]);
tin[x]=timer;
timer++;
return memo[x];
}
void dp2(int x, int t){
out[x]=t;
for (auto u : neigh2[x]) dp2(u,out[x]);
return;
}
struct node{
node* left; node* right;
int mx;
void update(){
this->mx=min(left->mx,right->mx);
}
};
struct Segtree {
int n;
node* root;
int base=1e9;
Segtree(int _n) {
this->n = _n;
root=new node{NULL,NULL,0};
}
void build(node* x, int l, int r, vector<int> const &a){
if(l==r) {
x->mx=a[l];
return;
}
int mid=(l+r)/2;
x->left=new node{NULL,NULL,0};
x->right=new node{NULL,NULL,0};
build(x->left,l,mid,a);
build(x->right,mid+1,r,a);
x->update();
}
Segtree(vector<int> const &a) : Segtree(a.size()) {
build(root,0,n-1,a);
}
int query(node* x, int l, int r, int qL, int qR){
if(r<qL||l>qR) return base;
if(l>=qL&&r<=qR) return x->mx;
int mid=(l+r)/2;
return min(query(x->left,l,mid,qL,qR),query(x->right,mid+1,r,qL,qR));
}
int query(int l, int r){
return query(root,0,n-1,l,r);
}
void update(node* x, int l, int r, int p, int v){
if(r<p||l>p) return;
if(l==r&&l==p) { x->mx=v; return; }
int mid=(l+r)/2;
update(x->left,l,mid,p,v);
update(x->right,mid+1,r,p,v);
x->update();
}
void update(int p, int v){
update(root,0,n-1,p,v);
}
};
signed main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int N,M,Q; cin >> N >> M >> Q;
memo.resize(N,-1);
neigh.resize(N);
neigh2.resize(N);
tin.resize(N);
out.resize(N);
timer=0;
vector<bool> leaf(N,true);
vector<bool> root(N,true);
for (int i = 0; i < M; i++)
{
int a,b; cin >> a >> b;
a--; b--;
neigh[b].push_back(a);
neigh2[a].push_back(b);
leaf[a]=false;
root[b]=false;
}
for (int i = 0; i < N; i++)
{
if(leaf[i]) dp(i);
}
for (int i = 0; i < N; i++)
{
if(root[i]) dp2(i,tin[i]);
}
Segtree seg(topo);
while (Q--)
{
int T,Y; cin >> T >> Y;
vector<int> y(Y);
for (int i = 0; i < Y; i++)
{
cin >> y[i];
y[i]--;
seg.update(tin[y[i]],1e9);
}
int q=seg.query(out[T-1],tin[T-1]);
cout << max(-1LL,topo[tin[T-1]]-q) << "\n";
for (int i = 0; i < Y; i++)
{
seg.update(tin[y[i]],topo[tin[y[i]]]);
}
}
return 0;
}
