#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i,n) for(int i=0;i<n;++i)
#define REP1(i,n) for(int i=1;i<=n;++i)
#define SZ(i) int(i.size())
#ifdef tmd
#define IOS()
#define debug(...) fprintf(stderr,"#%d: %s = ",__LINE__,#__VA_ARGS__),_do(__VA_ARGS__);
template<typename T> void _do(T &&x){cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T &&x, S &&...y){cerr<<x<<", ";_do(y...);}
template<typename It> ostream& _printRng(ostream &os,It bg,It ed)
{
os<<"{";
for(It it=bg;it!=ed;it++) {
os<<(it==bg?"":",")<<*it;
}
os<<"}";
return os;
}
template<typename T> ostream &operator << (ostream &os,vector<T> &v){return _printRng(os,v.begin(), v.end());}
template<typename T> ostream &operator << (ostream &os,pair<T,T> &v){return os<<"{"<<v.first<<","<<v.second<<"}";}
template<typename T> void pary(T bg, T ed){_printRng(cerr,bg,ed);cerr<<endl;}
#else
#define IOS() ios_base::sync_with_stdio(0);cin.tie(0);
#define endl '\n'
#define debug(...)
#define pary(...)
#endif
const int MAXN = 100005;
const ll MOD = 1000000007;
const ll INF = 0x3f3f3f3f3f3f3f3f;
const int K = sqrt(100005);
int n, m, q;
vector<int> edge[MAXN], redge[MAXN];
bool ban[MAXN];
vector<pair<int,int> > bst[MAXN];
bool used[MAXN];
void mrg (int to, int from) {
vector<pair<int,int> > res;
int ti = 0, fi = 0;
while (ti < SZ(bst[to]) || fi < SZ(bst[from])) {
if (ti == SZ(bst[to])) {
if (!used[bst[from][fi].first]) {
used[bst[from][fi].first] = true;
res.emplace_back(bst[from][fi]);
}
fi++;
} else if (fi == SZ(bst[from])) {
if (!used[bst[to][ti].first]) {
used[bst[to][ti].first] = true;
res.emplace_back(bst[to][ti]);
}
ti++;
} else {
if (bst[from][fi].second > bst[to][ti].second) {
if (!used[bst[from][fi].first]) {
used[bst[from][fi].first] = true;
res.emplace_back(bst[from][fi]);
}
fi++;
} else {
if (!used[bst[to][ti].first]) {
used[bst[to][ti].first] = true;
res.emplace_back(bst[to][ti]);
}
ti++;
}
}
}
for (auto p : res) {
used[p.first] = false;
}
if (res.size() > K) {
res.resize(K);
}
bst[to] = res;
}
void build () {
for (int i=1; i<=n; i++) {
bst[i].emplace_back(i, -1);
for (auto v : redge[i]) {
mrg(i, v);
}
for (auto &el : bst[i]) {
el.second++;
}
}
}
int qrySmall (int root) {
int ans = -1;
for (auto v : bst[root]) {
if (!ban[v.first]) {
ans = max(ans, v.second);
}
}
debug(root, bst[root]);
return ans;
}
int dp[MAXN];
int qryBig (int root) {
for (int i=1;i<=root;i++) {
dp[i] = ban[i] ? -1 : 0;
for (auto v : redge[i]) {
if (dp[v] != -1) {
dp[i] = max(dp[i], dp[v]+1);
}
}
}
return dp[root];
}
/*********************GoodLuck***********************/
int main () {
IOS();
cin >> n >> m >> q;
REP (i, m) {
int f, t;
cin >> f >> t;
edge[f].emplace_back(t);
redge[t].emplace_back(f);
}
build();
while (q--) {
int nd, sz;
cin >> nd >> sz;
vector<int> banList;
REP (i, sz) {
int v;
cin >> v;
ban[v] = true;
banList.emplace_back(v);
}
if (sz >= K) {
cout << qryBig(nd) << endl;
} else {
cout << qrySmall(nd) << endl;
}
for (auto v : banList) {
ban[v] = false;
}
}
}
