/////home/mohammed/.config/sublime-text-3/Packages/User

/*input

*/
#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <math.h>
#include <sstream>
#include <iterator>
#include <cstdlib>
#include <unordered_map>
#include <map>
#include <list>
#include <set>

using namespace std;
using bin = std::bitset<8>;

#define endl ("\n")
#define pi (3.141592653589)
#define mod 1000000007
#define int int64_t
#define float double
#define ll long long
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define all(c) c.begin(), c.end()
#define min3(a, b, c) min({a,b,c})
#define max3(a, b, c) max({a,b,c})
#define min4(a, b, c, d) min({a,b,c,d})
#define max4(a, b, c, d) max({a,b,c,d})
#define rrep(i, n) for(int i=n-1;i>=0;i--)
#define rep(i,n) for(int i=0;i<n;i++)
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr)
#define ld long double
#define scanArray(a,n) for(int i = 0; i < n; i++){cin >> a[i];}
#define coutArray(a,n) for(int i = 0; i < n; i++){cout << a[i] << " ";};cout << endl;
#define input(type, n) type n; cin>>n;


int32_t main()
{
	fast;
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif

	input(int, n);
	input(int, m);
	int received[m + 1] = {0};
	int check[m + 1] = {0};
	vector<vector<int>> y;
	y.resize(m + 1);
	input(int, q);
	while (q--) {
		input(int, x);
		received[x]++;
	}
	set<int> result;
	rep(i, n) {
		input(int, w);
		int r = 0;
		vector<int> v;
		rep(e, w) {
			input(int, x);
			if (received[x] > 0) {
				v.pb(x);
				r++;
			}
		}
		if (r == w) {
			result.insert(i);
			rep(e, w) {
				check[v[e]]++;
			}
			y[i] = v;
		}
	}
	vector<int> ans;
	for (auto i : result) {
		for (auto o : y[i]) {
			if (check[o] == 1) {
				ans.pb(i + 1);
				break;
			}
		}
	}
	cout << ans.size() << endl;
	for (auto i : ans) {
		cout << i << endl;
	}


}