#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
#ifdef DEBUG
#define debug(args...) _debug(args)
void _debug(const char* format, ...) {
va_list args;
va_start(args, format);
vprintf(format, args);
va_end(args);
}
#else
#define debug(args...)
#endif
#define INF 1000000005
#define LINF 1000000000000000005
#define MOD 1000000007
#define MAXN 200005
#define BLK 220
int n, m, q;
vi adj[MAXN];
vii far[MAXN];
int mxd[MAXN];
int t, y;
int c[MAXN];
bool blk[MAXN];
int dist[MAXN];
bool visited[MAXN];
vi topo;
void gettopo(int u) {
for (int v : adj[u]) {
if (visited[v]) continue;
visited[v] = 1;
gettopo(v);
}
topo.pb(u);
}
int main() {
scanf("%d%d%d", &n, &m, &q);
REP (i, 0, m) {
int s, e; scanf("%d%d", &s, &e);
adj[e].pb(s);
}
REP (i, 1, n + 1) {
mxd[i] = -1;
}
REP (i, 1, n + 1) {
vii all;
vi vs;
for (int v : adj[i]) {
for (auto [d, j] : far[v]) {
if (mxd[j] == -1) {
vs.pb(j);
}
mxto(mxd[j], d + 1);
}
}
for (int v : vs) {
all.pb(MP(mxd[v], v));
}
all.pb(MP(0, i));
sort(ALL(all), greater<ii>());
REP (j, 0, min(BLK, (int) all.size())) {
far[i].pb(all[j]);
}
for (int v : vs) {
mxd[v] = -1;
}
}
while (q--) {
scanf("%d%d", &t, &y);
REP (i, 0, y) {
scanf("%d", &c[i]);
blk[c[i]] = 1;
}
int ans = -1;
if (y >= BLK) {
topo.clear();
REP (i, 1, n + 1) {
visited[i] = 0;
dist[i] = -1;
}
visited[t] = 1;
gettopo(t);
dist[t] = 0;
RREP (i, topo.size() - 1, 0) {
debug(" %d\n", topo[i]);
for (int v : adj[topo[i]]) {
mxto(dist[v], dist[topo[i]] + 1);
debug(" %d: %d\n", v, dist[v]);
}
}
REP (i, 1, t + 1) {
if (dist[i] == -1 || blk[i]) continue;
mxto(ans, dist[i]);
}
} else {
REP (j, 0, far[t].size()) {
if (!blk[far[t][j].SE]) {
ans = far[t][j].FI;
break;
}
}
}
printf("%d\n", ans);
REP (i, 0, y) {
blk[c[i]] = 0;
}
}
return 0;
}
/*
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
*/
