#include <bits/stdc++.h>
#define optimize ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define ALL(x) x.begin(), x.end()
#define endl "\n"
#define ll long long
#define vi vector<int>
#define pii pair<int,int>
#define INF 0x3f3f3f3f
const int MAXN = 1e5 + 5;
const int SQRT = 350;
using namespace std;
int block[MAXN], tempo = 0;
vi trafo[MAXN];
set<pii> best[MAXN];
vi order;
int deg[MAXN];
void get_order(int n){
queue<int> fila;
for(int i=1; i<=n; i++)
if(deg[i] == 0)
fila.emplace(i);
while(!fila.empty())
{
auto u = fila.front();
fila.pop();
order.emplace_back(u);
for(auto v : trafo[u])
if(--deg[v] == 0)
fila.emplace(v);
}
reverse(ALL(order));
}
void precalc(){
for(auto u : order)
{
for(auto v : trafo[u])
{
best[u].emplace(-1, v);
for(auto [x, w] : best[v])
{
best[u].emplace(x-1, w);
if(best[u].size() > SQRT)
best[u].erase(--best[u].end());
}
}
while(best[u].size() > SQRT)
best[u].erase(--best[u].end());
}
}
int dp[MAXN];
int solve(int w){
for(auto u : order)
{
dp[u] = (block[u] == tempo ? -1 : 0);
for(auto v : trafo[u])
if(~dp[v])
dp[u] = max(dp[u], dp[v]+1);
if(u == w) break;
}
return dp[w];
}
int main(){
optimize;
int n, m, q;
cin >> n >> m >> q;
for(int i=0, u, v; i<m; i++)
{
cin >> u >> v;
trafo[v].emplace_back(u);
deg[u]++;
}
get_order(n);
precalc();
int t, y;
while(q--)
{
tempo++;
cin >> t >> y;
for(int i=0, x; i<y; i++)
cin >> x, block[x] = tempo;
int ans = -1;
for(auto [x, w] : best[t])
if(block[w] != tempo)
{
ans = -x;
break;
}
if(ans == -1) ans = solve(t);
cout << ans << endl;
}
return 0;
}
