///
/// NOW'S YOUR CHANCE TO BE A [[BIG SHOT]]!!
///
#include <bits/stdc++.h>
typedef long long ll;
typedef std::pair<int,int> pii;
#define F first
#define S second
using namespace std;
const int N = 100010;
static const int S = 310;
typedef vector<pii> vec;
vector<int> A[N];
int n, m;
bitset<N> busy;
vec dard[N];
int ans[N];
void mymerge(vec& a, vec& b)
{
static bitset<N> has; has.reset();
static vec ans(S);
int p1=0, p2=0;
for(int i = 0; i < S;)
{
has[N-1] = 0;
if(a[p1].F >= b[p2].F+1)
{
if(!has[a[p1].S]){
has[a[p1].S] = 1;
ans[i] = a[p1];
++i;
}
++p1;
} else {
if(!has[b[p2].S]){
has[b[p2].S] = 1;
ans[i] = {b[p2].F+1, b[p2].S};
++i;
}
++p2;
}
}
a.swap(ans);
}
void Do1()
{
for(int v = 0; v < n; ++v)
{
dard[v] = vec(S, pii{-N, N-1});
dard[v][0] = {0, v};
for(int u : A[v])
mymerge(dard[v], dard[u]);
}
}
void Do2()
{
for(int v = 0; v < n; ++v)
{
ans[v] = busy[v]?-N:0;
for(int u : A[v])
ans[v] = max(ans[v], ans[u]+1);
}
}
int main()
{
ios::sync_with_stdio(false); cin.tie(0);
int q;
cin >> n >> m >> q;
for(int i = 0; i < m; ++i)
{
int s, t;
cin >> s >> t;
A[t-1].push_back(s-1);
}
Do1();
while(q--)
{
int t, y;
cin >> t >> y; --t;
vector<int> kooft(y);
for(int i = 0; i < y; ++i)
cin >> kooft[i],
busy[kooft[i]-1] = 1;
if(y < S)
{
int ans = 0;
while(busy[dard[t][ans].S])
++ans;
cout << (dard[t][ans].S == N-1? -1: dard[t][ans].F) << '\n';
}
else
{
Do2();
cout << (ans[t]<0?-1:ans[t]) << '\n';
}
for(int i = 0; i < y; ++i)
busy[kooft[i]-1] = 0;
}
}
