#include <iostream>
using namespace std;
int n,m,p,q;
int fa1[10005],fa2[10005];
int find1(int x)
{
    if(fa1[x] == x) return x;
    return fa1[x] == find1(fa1[x]);
}
int find2(int x)
{
    if(fa2[x] == x) return x;
    return fa2[x] == find2(fa2[x]);
}
int main()
{
    cin >> n >> m >> p >> q;
    for(int i = 1;i <= n;i ++) fa1[i] = i;
    for(int i = 1;i <= m;i ++) fa2[i] = i;
    while(p --)
    {
        int x,y;
        cin >> x >> y;
        fa1[find1(x)] = find1(y);
    }
    while(q --)
    {
        int x,y;
        cin >> x >> y;
        fa2[find2(-x)] = find2(-y);
    }
    int cnt1 = 0,cnt2 = 0;
    for(int i = 1;i <= n;i ++) if(find1(i) == find1(1)) cnt1 ++;
    for(int i = 1;i <= m;i ++) if(find2(i) == find2(1)) cnt2 ++;
    cout << min(cnt1,cnt2) << endl;
    return 0;
}

代码如上，求调