#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 300
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];
vi vs;
bool isPos(int x) {
int cnt = 0;
for (int i : vs) {
cnt += mxd[i] >= x;
}
return cnt <= BLK;
}
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) {
vs.clear();
for (int v : adj[i]) {
for (auto [d, j] : far[v]) {
if (mxd[j] == -1) {
vs.pb(j);
}
mxto(mxd[j], d + 1);
}
}
vs.pb(i);
mxd[i] = 0;
int lo = 0, hi = n, mid;
// minimum number where there are <= BLK stuff with mxd >= mid
while (lo < hi) {
mid = lo + hi >> 1;
if (isPos(mid)) {
hi = mid;
} else {
lo = mid + 1;
}
}
vi ex;
for (int v : vs) {
if (mxd[v] >= hi) {
far[i].pb(MP(mxd[v], v));
} else if (mxd[v] == hi - 1) {
ex.pb(v);
}
}
while (far[i].size() < BLK && !ex.empty()) {
int v = ex.back(); ex.pop_back();
far[i].pb(MP(mxd[v], v));
}
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 - 5) {
REP (i, 1, n + 1) {
dist[i] = -1;
}
dist[t] = 0;
RREP (i, t, 1) {
if (dist[i] == -1) continue;
for (int v : adj[i]) {
mxto(dist[v], dist[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]) {
mxto(ans, far[t][j].FI);
}
}
}
printf("%d\n", ans);
REP (i, 0, y) {
blk[c[i]] = 0;
}
}
return 0;
}
