#include<cstdio>
#include<iostream>
#include<cstring>
#include<queue>
#include<vector>
#include<algorithm>
using namespace std;
const int maxn = 1e6 + 7;
const int inf = 0x3f3f3f3f;
template<class T>inline void read(T &res)
{
char c;T flag=1;
while((c=getchar())<‘0‘||c>‘9‘)if(c==‘-‘)flag=-1;res=c-‘0‘;
while((c=getchar())>=‘0‘&&c<=‘9‘)res=res*10+c-‘0‘;res*=flag;
}
struct edge{int from,to,cap,flow;};
struct isap
{
int n,s,t,p[maxn],d[maxn],cur[maxn],num[maxn];
bool vis[maxn];
vector<int>g[maxn];
vector<edge>edges;
void init(int n,int s,int t) {
this->n = n;
this->s = s;
this->t = t;
for(int i = 1;i <= n;i++) g[i].clear();
edges.clear();
}
void addegde(int from,int to,int cap) {
edges.push_back((edge){from, to, cap, 0});
edges.push_back((edge){to, from, 0, 0});
int m = edges.size();
g[from].push_back(m-2);
g[to].push_back(m-1);
}
int augment() {///找增广路
int x = t,a = inf;
while(x!=s) {
a = min(a, edges[p[x]].cap - edges[p[x]].flow);
x = edges[p[x]].from;
}
x=t;
while(x != s) {
edges[p[x]].flow += a;
edges[p[x]^1].flow = -a;
x = edges[p[x]].from;
}
return a;
}
int maxflow() {///更新最大流
int flow = 0;
memset(num, 0, sizeof(num));
memset(cur, 0, sizeof(cur));
for(int i = 1; i <= n; i++) num[d[i]]++;
int x = s;
while(d[s] < n) {///最长的一条链上，最大的下标是nv-1，如果大于等于nv说明已断层
if(x == t) {
flow += augment();
x = s;//回退
}
bool ok = 0;
for(int i = cur[x]; i < g[x].size(); i++) {
edge &e = edges[g[x][i]];
if(d[x] == d[e.to] + 1 && e.cap > e.flow) {
p[e.to] = g[x][i];
cur[x] = i;x = e.to;
ok = 1;
break;
}
}
if(!ok) {
int m = n-1;
for(int i = 0; i < g[x].size();i++) {
edge &e=edges[g[x][i]];
if(e.cap>e.flow) m=min(m,d[e.to]);
}
num[d[x]]--;
if(!num[d[x]]) break;
d[x] = m+1;
num[d[x]]++;
cur[x] = 0;
if(x != s) x = edges[p[x]].from;
}
}
return flow;
}
}ISAP;
int n, p, q;
int s, t;
int main()
{
read(n), read(p), read(q);
s = 2*n+q+p+1;
t = s+1;
ISAP.init(2 * n + p + q + 7, s, t);
int m2;
read(m2);
for ( int i = 1; i <= m2; ++i ) {
int u, v;
read(u);
read(v);
ISAP.addegde(v, u + p, 1);
}
read(m2);
for ( int i = 1; i <= m2; ++i ) {
int u, v;
read(u);read(v);
ISAP.addegde(n + p + u, v + p + 2 * n, 1);
}
for ( int i = 1; i <= n; ++i ) {
ISAP.addegde(p + i, n + p + i, 1);
}
for ( int i = 1; i <= q; ++i ) {
ISAP.addegde(s, i, 1);
}
for ( int i = 1; i <= p; ++i ) {
ISAP.addegde(n * 2 + p + i, t, 1);
}
// while(bfs()) {
// Dinic();
// }
printf("%d\n",ISAP.maxflow());
return 0;
}
