#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
#define pb push_back
#define pii pair<int, int>
#define pll pair<ll, ll>
#define st first
#define nd second
#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define debug false
const int K = 300;
const int MAXN = 100 * 1000 + 17 + K * 50;
pii dp[MAXN][K];
pii akt[K];
vector<int> graf[MAXN];
bool bylo[MAXN];
vector<int> vec;
int dp2[MAXN];
int main () {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n, m, q;
cin >> n >> m >> q;
int a, b;
for (int i = 0; i < m; i ++) {
cin >> a >> b;
graf[b].pb(a);
}
for (int i = 1; i <= n; i ++) {
for (int j = 0; j < K; j ++) {
dp[i][j] = {-MAXN, n + j + 1};
}
dp[i][0] = {0, i};
for (auto x : graf[i]) {
int ind1 = 0, ind2 = 0;
for (int j = 0; j < K; j ++) {
while (bylo[dp[i][ind1].nd]) {
ind1 ++;
}
while (bylo[dp[x][ind2].nd]) {
ind2 ++;
}
if (dp[i][ind1].st >= dp[x][ind2].st + 1) {
akt[j] = {dp[i][ind1].st, dp[i][ind1].nd};
bylo[dp[i][ind1].nd] = true;
ind1 ++;
} else {
akt[j] = {dp[x][ind2].st + 1, dp[x][ind2].nd};
bylo[dp[x][ind2].nd] = true;
ind2 ++;
}
}
for (int j = 0; j < K; j ++) {
bylo[dp[i][j].nd] = false;
bylo[dp[x][j].nd] = false;
}
swap(akt, dp[i]);
}
}
int t, k, x;
while (q --) {
cin >> t >> k;
vec.clear();
for (int i = 0; i < k; i ++) {
cin >> x;
vec.pb(x);
bylo[x] = true;
}
if (k < K) {
for (int i = 0; i < K; i ++) {
if (!bylo[dp[t][i].nd]) {
if (dp[t][i].st < 0) {
cout << -1 << "\n";
} else {
cout << dp[t][i].st << "\n";
}
break;
}
}
} else {
for (int i = 1; i <= n; i ++) {
if (!bylo[i]) {
dp2[i] = 0;
} else {
dp2[i] = -MAXN;
}
for (auto x : graf[i]) {
dp2[i] = max(dp2[i], dp2[x] + 1);
}
}
if (dp2[t] < 0) {
cout << -1 << "\n";
} else {
cout << dp2[t] << "\n";
}
}
for (auto x : vec) {
bylo[x] = false;
}
}
return 0;
}
