#include <bits/stdc++.h>
using namespace std;
const int BUCKET_SIZE = 302;
const int MAX_N = 100002;
vector<int> adj[MAX_N], inv[MAX_N];
pair<int, int> Town[MAX_N][BUCKET_SIZE];
pair<int, int> tmp[BUCKET_SIZE];
bool Used[MAX_N];
int dp[MAX_N];
int main()
{
ios::sync_with_stdio(false); cin.tie(NULL);
int N, M, Q; cin >> N >> M >> Q;
for(int i=1;i<=M;i++)
{
int S, E; cin >> S >> E;
adj[S].push_back(E);
inv[E].push_back(S);
}
for(int i=1;i<=N;i++) Town[i][0] = {i, 0};
for(int i=1;i<=N;i++)
{
for(int j : adj[i])
{
int x=0, y=0;
stack<int> st;
for(int b=0;b<BUCKET_SIZE;b++) tmp[b] = {0, 0};
for(int b=0;b<BUCKET_SIZE;)
{
int A = Town[i][x].first, B = Town[i][x].second + 1;
int C = Town[j][y].first, D = Town[j][y].second;
if(A == 0 && C == 0) break;
if(A == 0 || D > B)
{
if(!Used[C])
{
st.push(C);
Used[C] = true;
tmp[b++] = {C, D};
}
y++;
}
else
{
if(!Used[A])
{
st.push(A);
Used[A] = true;
tmp[b++] = {A, B};
}
x++;
}
}
while(!st.empty())
{
Used[st.top()] = false;
st.pop();
}
for(int b=0;b<BUCKET_SIZE;b++)
{
Town[j][b] = tmp[b];
}
}
}
for(int i=1;i<=Q;i++)
{
int T, Y;
cin >> T >> Y;
if(Y < BUCKET_SIZE)
{
stack<int> st;
for(int j=0;j<Y;j++)
{
int k; cin >> k;
Used[k] = true;
st.push(k);
}
int ans = -1;
for(int b=0;b<BUCKET_SIZE;b++)
{
if(Town[T][b].first == 0) break;
if(!Used[Town[T][b].first])
{
ans = Town[T][b].second;
break;
}
}
while(!st.empty())
{
Used[st.top()] = false;
st.pop();
}
cout << ans << "\n";
}
else
{
stack<int> st;
for(int j=0;j<Y;j++)
{
int k; cin >> k;
Used[k] = true;
st.push(k);
}
int ans = -1;
for(int j=1;j<=N;j++) dp[j] = -1;
dp[T] = 0;
for(int j=T;j>=2;j--) if(dp[j] != -1) for(int k : inv[j]) dp[k] = max(dp[k], dp[j] + 1);
for(int j=1;j<=N;j++) if(!Used[j]) ans = max(ans, dp[j]);
while(!st.empty())
{
Used[st.top()] = false;
st.pop();
}
cout << ans << "\n";
}
}
}
