#include <bits/stdc++.h>
#define int long long
#define pb(x) push_back(x)
using namespace std;
const int N = 100005;
typedef pair<int,int> ii;

int n,m,par[N],cnt=0,num[N],low[N];
vector<int> a[N],aa,bb;
int ans=0;
int k,l;
int c[3][N];

void dfs(int u)
{
    num[u] = low[u] = ++cnt;
    for(int &v : a[u])
    {
        if (par[u] == v) continue;
        if (par[v]) low[u]=min(low[u],num[v]);
        else
        {
            par[v] = u;
            dfs(v);
            c[1][u] += c[1][v];
            c[2][u] += c[2][v];
            low[u]=min(low[u],low[v]);
            if (low[v] == num[v]) {
                if (c[1][v] == 0 || c[1][v] == k)
                {
                    ans++;
                }
                else if (c[2][v] == 0 || c[2][v] == l)
                {
                    ans++;
                }
            }
        }
    }
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    freopen("net.inp","r",stdin);
    freopen("net.out","w",stdout);
    cin >> n >> m >> k >> l;
    for(int i=1; i<=k; ++i)
    {
        int x;
        cin >> x;
        c[1][x]=1;
    }
    for(int i=1; i<=l; ++i)
    {
        int x;
        cin >> x;
        c[2][x]=1;
    }
    for(int i=1; i<=m; ++i)
    {
        int u, v;
        cin >> u >> v;
        a[u].pb(v);
        a[v].pb(u);
    }
    for(int i=1; i<=n; ++i)
    {
        if (!par[i])
        {
            par[i] = -1;
            dfs(i);
        }
    }
    cout << ans << endl;
    return 0;
}