/*
* In the name of God
*
* Author: Farbod Doost
* Last Modified: Sun, 06 Nov 2022 (12:48:25)
*
*/
#include <iostream>
#include <vector>
using namespace std;
const int N = 1e5 + 1;
int n, m, dp[N];
bool vis[N];
vector <int> adj[N];
signed main()
{
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
int q;
cin >> n >> m >> q;
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v, u--, v--;
adj[v].push_back(u);
}
int r;
while (q--) {
int k, c;
cin >> r >> k, r--;
for (int i = 0; i < k; i++)
cin >> c, vis[c - 1] = 1;
}
dp[r] = 0;
for (int i = r - 1; i >= 0; i--) {
dp[i] = -1;
for (auto x: adj[i])
if (x <= r)
dp[i] = max(dp[i], dp[x] + 1);
}
int ans = -1;
for (int i = 0; i <= r; i++)
if (!vis[i])
ans = max(ans, dp[i]);
cout << ans;
return 0;
}
