#include <bits/stdc++.h>
using namespace std;
#define ar array
#define sz(v) int(std::size(v))
using i64 = long long;
using pii = pair<int, int>;
const int N = 1e5, B = 100;
int n, m, q;
vector<int> from[N];
pii dp[N][B], tmp[B];
void merge(pii *one, pii *two, pii *me) {
static bool used[N];
int i = 0, x = 0, y = 0;
for (; i < B; i++) {
while (x < B && one[x].second != -1 && used[one[x].second]) x++;
while (y < B && two[y].second != -1 && used[two[y].second]) y++;
if ((x == B || one[x].second == -1) && (y == B || two[y].second == -1)) break;
if (x == B || one[x].second == -1) me[i] = {two[y].first + 1, two[y].second}, y++;
else if (y == B || two[y].second == -1) me[i] = one[x++];
else if (one[x].first > two[y].first + 1) me[i] = one[x++];
else me[i] = {two[y].first + 1, two[y].second}, y++;
used[me[i].second] = true;
}
for (int j = i; j < B; j++) me[j] = {-1, -1};
for (int j = i - 1; j >= 0; j--) used[me[j].second] = false;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> m >> q;
while (m--) {
int l, r;
cin >> l >> r, l--, r--;
from[r].push_back(l);
}
for (int i = 0; i < n; i++) {
fill(dp[i], dp[i] + B, pii{-1, -1});
dp[i][0] = {0, i};
for (int j : from[i]) merge(dp[i], dp[j], tmp), swap(dp[i], tmp);
}
while (q--) {
static bool dead[N];
int i, k;
cin >> i >> k, i--;
vector<int> v(k);
for (int &i : v) cin >> i, i--, dead[i] = true;
int ans = -1;
if (k < B) {
for (int h = 0; h < B; h++) {
if (dp[i][h].second == -1) break;
if (!dead[dp[i][h].second]) {
ans = dp[i][h].first;
break;
}
}
} else {
static int dp[N];
fill(dp, dp + n, -1);
dp[i] = 0;
for (int j = i; j >= 0; j--) if (~dp[i]) {
if (!dead[j]) ans = max(ans, dp[j]);
for (int k : from[j]) dp[k] = max(dp[k], dp[j] + 1);
}
}
cout << ans << '\n';
for (int i : v) dead[i] = false;
}
}
