//Challenge: Accepted
#include <unistd.h>
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#define ll long long
#define maxn 100005
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
inline char RC(){
const int S = 1<<20;
static char buf[S], *p = buf, *q = buf;
if(p==q&&(q=(p=buf)+read(0, buf,S))==buf) return -1;
return *p++;
}
inline void rint(int &ret) {
char c;
ret = 0;
do {c = RC();} while (c < '0' || c > '9');
do {ret = (ret<<3)+(ret<<1) + c-'0';c=RC();} while (c>='0'&&c<='9');
}
char OB[1<<20];
int outp;
inline void pint(int a) {
int d = -1;
if (a < 0) OB[outp++] = '-', a = -a;
if (!a) {OB[outp++] = '0';OB[outp++] = '\n';return;}
char c[19];
while (a) {c[++d] = '0' + a%10;a /= 10;}
for (int i=d;i >= 0;i--) OB[outp++] = c[i];
OB[outp++] = '\n';
}
const int siz = 140;
vector<int> adj[maxn], from[maxn];
vector<pii> pnt[maxn], tmp;
inline bool cmp (pii a, pii b) {
return a.ss > b.ss;
}
int dp[maxn];
bool part[maxn], found[maxn];
void getdp(int n, int id) {
for (int i = 1;i <= id;i++) dp[i] = 0;
for (int i = 1;i <= id;i++) {
for (int v:adj[i]) {
dp[v] = max(dp[v], (dp[i] == 0 ? (part[i] ? -1 : 0) : dp[i]) + 1);
}
}
}
void merge(int a, int b) {
vector<pii> ret;
int n = pnt[a].size(), m = pnt[b].size(), ind = 0;
for (int i = 0;i < n;i++) {
while (ind < m && pnt[b][ind].ss + 1 > pnt[a][i].ss) {
if (!found[pnt[b][ind].ff]) {
found[pnt[b][ind].ff] = 1;
ret.push_back(make_pair(pnt[b][ind].ff, pnt[b][ind].ss + 1));
}
ind++;
if (ret.size() > siz) break;
}
if (!found[pnt[a][i].ff]) {
found[pnt[a][i].ff] = 1;
ret.push_back(pnt[a][i]);
}
if (ret.size() > siz) break;
}
while (ind < m) {
if (!found[pnt[b][ind].ff]) {
found[pnt[b][ind].ff] = 1;
ret.push_back(make_pair(pnt[b][ind].ff, pnt[b][ind].ss + 1));
}
ind++;
if (ret.size() > siz) break;
}
for (auto i:ret) found[i.ff] = 0;
if (ret.size() > siz) ret.resize(siz);
pnt[a] = ret;
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(0);
int n, m, q;
rint(n), rint(m), rint(q);
for (int i = 0;i < m;i++) {
int a, b;
rint(a), rint(b);
adj[a].push_back(b);
from[b].push_back(a);
}
for (int i = 1;i <= n;i++) {
pnt[i].push_back(make_pair(i, 0));
for (int v:from[i]) {
merge(i, v);
}
}
getdp(n, n);
while (q--) {
int ind, yi;
rint(ind), rint(yi);
vector<int> val;
for (int i = 0;i < yi;i++) {
int x;
rint(x);
if (x <= ind) part[x] = 1, val.push_back(x);
}
if (yi >= siz) {
getdp(n, ind);
if (part[ind] && dp[ind] == 0) pint(-1);
else pint(dp[ind]);
} else {
int ans = -1;
for (auto v:pnt[ind]) {
if (!part[v.ff]) ans = max(ans, v.ss);
}
pint(ans);
}
for (int i:val) part[i] = 0;
}
write(1, OB, outp);
}
/*
5 6 3
1 2
2 4
3 4
1 3
3 5
4 5
4 1 1
5 2 2 3
2 3 1 4 5
*/
