#include <cstdio>
#include <iostream>
#include <vector>
#include <list>
#include <string>
#include <set>
#include <map>
#include <algorithm>
#include <fstream>
#include <cmath>
#include <queue>
#include <stack>
#include <cassert>
#include <cstring>
#include <climits>
#include <functional>
#include <cstdlib>
#include <complex>
#include <array>
#include <iomanip>
#include <bitset>
#define fileIO(name) if(fopen(name".in", "r")) {freopen(name".in", "r", stdin); freopen(name".out", "w", stdout);}
using namespace std;
const int MAXN = 2e5 + 11;
using ll = long long;
const int P = 31;
const ll mod1 = 1e9 + 7;
const ll mod2 = 998244353;
using ld = long double;
const ld EPS = 1e-5;
using pii = pair<int, int>;
const int K = 300;
int n, m, q;
vector<pair<int, int>> good[MAXN];
bool vis[MAXN];
bool bussy[MAXN];
vector<int> adj[MAXN];
vector<int> radj[MAXN];
int dp[MAXN];
int main()
{
cin.tie(0);
cout.tie(0);
ios::sync_with_stdio(0);
//fileIO("paintbarn");
cin >> n >> m >> q;
for (int i = 0; i < m; i++)
{
int a, b;
cin >> a >> b;
adj[a].push_back(b);
radj[b].push_back(a);
}
for (int i = 1; i <= n; i++)
{
for (auto x : radj[i])
{
vector<pair<int, int>>fin;
good[x].push_back({ 0,x });
int a = 0;
int b = 0;
int sa = good[x].size();
int sb = good[i].size();
while (fin.size() < K && (a < sa && b < sb))
{
if (good[x][a].first + 1 >= good[i][b].first)
{
fin.push_back({ good[x][a].first + 1,
good[x][a].second });
vis[good[x][a].second] = true;
a++;
}
else
{
fin.push_back({ good[i][b].first,
good[i][b].second });
vis[good[i][b].second] = true;
b++;
}
while (a < sa && vis[good[x][a].second])
a++;
while (b < sb && vis[good[i][b].second])
b++;
}
while (fin.size() < K && a < sa)
{
fin.push_back({ good[x][a].first + 1,
good[x][a].second });
vis[good[x][a].second] = true;
a++;
while (a < sa && vis[good[x][a].second])
a++;
}
while (fin.size() < K && b < sb)
{
fin.push_back({ good[i][b].first,good[i][b].second });
vis[good[i][b].second] = true;
b++;
while (b < sb && vis[good[i][b].second])
b++;
}
for (auto v : fin)
vis[v.second] = false;
good[i] = fin;
fin.clear();
}
}
while (q--)
{
int t, y;
cin >> t >> y;
vector<int> c(y);
for (int i = 0; i < y; i++)
{
cin >> c[i];
bussy[c[i]] = true;
}
int ans = -1;
if (y < K)
{
for (auto x : good[t])
{
if (!bussy[x.second])
ans = max(ans, x.first);
}
if (!bussy[t])
ans = max(ans, 0);
}
else
{
for (int i = 1; i <= n; i++)
dp[i] = -1;
dp[t] = 0;
if (!bussy[t])
ans = 0;
for (int i = t - 1; i; i--)
{
for (auto x : adj[i])
if (dp[x] != -1)
dp[i] = max(dp[i], dp[x] + 1);
if (!bussy[i])
ans = max(ans, dp[i]);
}
}
for (int i = 0; i < y; i++)
bussy[c[i]] = false;
cout << ans << '\n';
}
return 0;
}
