#include <bits/stdc++.h>
//#include <bits/debug.hpp>
#define ll long long
#define all(x) x.begin(), x.end()
#define Neco "Bitaro Party"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7
using namespace std;
const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;
const int Sqrt = 371;
int n, m, q;
int vis[maxn], spe[maxn], dist[maxn];
vector<int> edges[maxn];
vector<pair<int, int>> dp[maxn];
void CASE1(int u, int del) {
for(auto [w, x] : dp[u]) if(spe[x] != del) {
return cout << w << '\n', void();
}
cout << -1 << '\n';
}
void CASE2(int u, int del) {
fi(i, 1, n) dist[i] = -1;
fi(x, 1, n) {
if(spe[x] != del) dist[x] = 0;
for(int y : edges[x]) if(dist[y] != -1) {
dist[x] = max(dist[x], dist[y] + 1);
}
}
cout << dist[u] << '\n';
}
void solve()
{
cin >> n >> m >> q;
fi(i, 1, m) {
int x, y; cin >> x >> y;
edges[y].push_back(x);
}
vector<int> P;
fi(i, 1, n) {
P = {i}, dist[i] = 0;
for(int u : edges[i]) for(auto [w, x] : dp[u]) {
if(vis[x] == i) dist[x] = max(dist[x], w + 1);
else dist[x] = w + 1, vis[x] = i, P.push_back(x);
}
sort(all(P), [](const int x, const int y) { return dist[x] < dist[y]; } );
while(dp[i].size() <= Sqrt && !P.empty()) {
dp[i].push_back({dist[P.back()], P.back()});
P.pop_back();
}
}
fi(i, 1, q) {
int x, u, T; cin >> x >> T;
fi(_, 1, T) cin >> u, spe[u] = i;
if(T < Sqrt) CASE1(x, i);
else CASE2(x, i);
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
if(fopen(Neco".inp", "r")) {
freopen(Neco".inp", "r", stdin);
freopen(Neco".out", "w", stdout);
}
int nTest = 1;
// cin >> nTest;
while(nTest--)
{
solve();
}
return 0;
}
