#define _FORTIFY_SOURCE 0
#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx")
#pragma GCC optimize("inline")
#pragma GCC optimize("-fgcse")
#pragma GCC optimize("-fgcse-lm")
#pragma GCC optimize("-fipa-sra")
#pragma GCC optimize("-ftree-pre")
#pragma GCC optimize("-ftree-vrp")
#pragma GCC optimize("-fpeephole2")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-fsched-spec")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-falign-jumps")
#pragma GCC optimize("-falign-loops")
#pragma GCC optimize("-falign-labels")
#pragma GCC optimize("-fdevirtualize")
#pragma GCC optimize("-fcaller-saves")
#pragma GCC optimize("-fcrossjumping")
#pragma GCC optimize("-fthread-jumps")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-fwhole-program")
#pragma GCC optimize("-freorder-blocks")
#pragma GCC optimize("-fschedule-insns")
#pragma GCC optimize("inline-functions")
#pragma GCC optimize("-ftree-tail-merge")
#pragma GCC optimize("-fschedule-insns2")
#pragma GCC optimize("-fstrict-aliasing")
#pragma GCC optimize("-fstrict-overflow")
#pragma GCC optimize("-falign-functions")
#pragma GCC optimize("-fcse-skip-blocks")
#pragma GCC optimize("-fcse-follow-jumps")
#pragma GCC optimize("-fsched-interblock")
#pragma GCC optimize("-fpartial-inlining")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("-freorder-functions")
#pragma GCC optimize("-findirect-inlining")
#pragma GCC optimize("-fhoist-adjacent-loads")
#pragma GCC optimize("-frerun-cse-after-loop")
#pragma GCC optimize("inline-small-functions")
#pragma GCC optimize("-finline-small-functions")
#pragma GCC optimize("-ftree-switch-conversion")
#pragma GCC optimize("-foptimize-sibling-calls")
#pragma GCC optimize("-fexpensive-optimizations")
#pragma GCC optimize("-funsafe-loop-optimizations")
#pragma GCC optimize("inline-functions-called-once")
#pragma GCC optimize("-fdelete-null-pointer-checks")
#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
constexpr int maxn = 1e5 + 10;
int n, m, q, grau2[maxn];
int dp[maxn];
vector<int> grafo[maxn], g[maxn];
bool mark[maxn], mark2[maxn], tem[maxn];
vector<pii> guarda[maxn];
#define gc getchar_unlocked
inline int scan() {
int x = gc(), n = 0;
for(;x < '0' || x > '9'; x = gc()) {}
for(;x >= '0' && x <= '9'; x = gc()) n = 10*n + x - '0';
return n;
}
int dfs_dp(int u) {
if(dp[u] != -1) return dp[u];
tem[u] = !mark[u];
int& ans = dp[u];
ans = 0;
for(int v : g[u])
ans = max(ans, dfs_dp(v)+tem[v]), tem[u] |= tem[v];
return ans;
}
int main() {
ios::sync_with_stdio(false), cin.tie(0);
n = scan(), m = scan(), q = scan();
int sq = 200;
for (int i = 1; i <= m; i++) {
int a, b;
a = scan(), b = scan();
grafo[a].push_back(b);
g[b].push_back(a);
grau2[b]++;
}
{ // precompute unordered map
queue<int> fila;
for (int i = 1; i <= n; i++) {
guarda[i].push_back({0, i});
if (grau2[i] == 0) fila.push(i);
guarda[i].reserve(sq+1);
}
vector<pii> aux;
aux.reserve(2*sq);
while (!fila.empty()) {
int u = fila.front();
fila.pop();
for(auto& e : guarda[u])
e.first++;
for(auto v : grafo[u]) {
aux.resize(guarda[u].size() + guarda[v].size());
grau2[v]--;
if (grau2[v] == 0) fila.push(v);
merge(guarda[u].begin(), guarda[u].end(),
guarda[v].begin(), guarda[v].end(), aux.begin(), greater<pii>());
guarda[v].clear();
for(auto it = aux.begin(); it != aux.end() && guarda[v].size() <= sq; it++)
if(!mark[it->second]) guarda[v].push_back(*it), mark[it->second] = true;
for (auto e : guarda[v])
mark[e.second] = false;
}
for (auto& e : guarda[u])
e.first--;
}
}
for (int i = 1; i <= q; i++) {
int t, y;
t = scan(), y= scan();
vector<int> query(y);
for (int i = 0; i < y; i++)
query[i] = scan();
if (y >= sq) {
memset(dp, -1, sizeof dp);
for (int i = 0; i < y; i++)
mark[query[i]] = true;
cout << (dfs_dp(t)==0&&mark[t]?-1:dp[t]) << '\n';
for (int i = 0; i < y; i++)
mark[query[i]] = false;
} else {
for (int j = 0; j < y; j++)
mark2[query[j]] = true;
int ans = -1;
for (auto it = guarda[t].begin(); it != guarda[t].end(); it++) {
if (!mark2[it->second]) {
ans = it->first;
break;
}
}
for (int j = 0; j < y; j++)
mark2[query[j]] = false;
cout << ans << '\n';
}
}
return 0;
}
