net

//Nguyen Huu Hoang Minh
#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 200005
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "net"
#define int long long

using namespace std;

typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;

int n, m, k, l;
vector<int> a[N];
int na[N], nb[N];
int num[N], low[N], cnt;
int par[N];
int ca[N], cb[N];
int ans;

void readfile()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    if (fopen(Task".inp","r"))
    {
        freopen(Task".inp","r",stdin);
        freopen(Task".out","w",stdout);
    }
    cin >> n >> m >> k >> l;
    for(int i=1; i<=k; i++)
    {
        int x;
        cin >> x;
        na[x] = 1;
    }
    for(int i=1; i<=l; i++)
    {
        int x;
        cin >> x;
        nb[x] = 1;
    }
    for(int i=1; i<=m; i++)
    {
        int u, v;
        cin >> u >> v;
        a[u].pb(v);
        a[v].pb(u);
    }
}

void dfs(int u)
{
    num[u] = low[u] = ++cnt;
    ca[u] = (na[u])?1:0;
    cb[u] = (nb[u])?1:0;
    for(auto v : a[u])
    {
        if (v==par[u]) continue;
        if (par[v]) low[u] = min(low[u],num[v]);
        else{
            par[v] = u;
            dfs(v);
            low[u] = min(low[u],low[v]);
            ca[u] += ca[v];
            cb[u] += cb[v];
            if (low[v] == num[v])
            {
                int lea = k-ca[v];
                int leb = l-cb[v];
                int res = min(lea,leb);
                res = min(res,ca[v]);
                res = min(res,cb[v]);
                if (res==0){
                    ans++;
                }
            }
        }
    }
}

void preproc()
{
    for(int i=1; i<=n; i++)
    {
        if (!par[i])
        {
            par[i] = -1;
            dfs(i);
        }
    }
}

void proc()
{
    cout << ans;
}

signed main()
{
    readfile();
    preproc();
    proc();
    return 0;
}