#include <bits/stdc++.h>
#define FOR(i, k, n) for(int i = k; i <= n; i++)
#define FORD(i, k, n) for(int i = k; i >= n; i--)
#define REP(i, n) for(int i = 0; i < n; i++)
#define REPD(i, n) for(int i = n - 1; i >= 0; i--)
#define ii pair<int,int>
#define trii pair<int,ii>
#define fi first
#define se second
#define int long long
#define vi vector<int>
#define pb push_back
#define all(x, n) (x) + 1, (x) + n + 1
#define allv(x) (x).begin(), (x).end()
#define vii vector<ii>
#define sz(x) ((int)x.size())
using namespace std;
const int N = 1e5 + 5;
const int B = 100;
vi rg[N];
vii lps[N];
int bs[N];
int dp[N];
int n, m, q;
bool ava[N];
int from[N];
void cal(int t)
{
FOR(i, 1, t)
{
if (ava[i]) dp[i] = 0;
else dp[i] = -1;
for (int j : rg[i])
{
if (dp[j] != -1) dp[i] = max(dp[i], dp[j] + 1);
}
}
cout << dp[t] << '\n';
}
int32_t main()
{
iostream::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n >> m >> q;
FOR(i, 1, m)
{
int u, v; cin >> u >> v;
rg[v].pb(u);
}
memset(from, -1, sizeof(from));
FOR(i, 1, n)
{
static vi fidx;
fidx.clear();
lps[i].pb({0, i});
for (int j : rg[i])
{
for (ii &x : lps[j])
{
if (from[x.se] == -1)
{
fidx.pb(x.se);
from[x.se] = x.fi + 1;
}
else
{
from[x.se] = max(from[x.se], x.fi + 1);
}
}
}
for (int x : fidx)
{
lps[i].pb({from[x], x});
}
sort(allv(lps[i])); reverse(allv(lps[i]));
while(sz(lps[i]) > B) lps[i].pop_back();
for (int x : fidx)
{
from[x] = -1;
}
}
memset(ava, true, sizeof ava);
FOR(i, 1, q)
{
int t, y; cin >> t >> y;
FOR(j, 1, y)
{
cin >> bs[j];
}
FOR(i, 1, y) ava[bs[i]] = false;
if (y >= B)
{
cal(t);
}
else
{
bool f = false;
REP(i, sz(lps[t]))
{
if (ava[lps[t][i].se])
{
cout << lps[t][i].fi << '\n';
f = true;
break;
}
}
if (!f)
{
cout << -1 << '\n';
}
}
FOR(i, 1, y) ava[bs[i]] = true;
}
return 0;
}
