#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pli = pair<ll,int>;

int main(){
    int n, k, m, p; cin >> n >> k >> m >> p;
    vector<vector<int>> g(n);
    while (m--){
        int u, v; cin >> u >> v; u--, v--;
        g[u].emplace_back(v);
        g[v].emplace_back(u);
    }
    vector<ll> s(n);
    for (int i = 0; i < n; i++) cin >> s[i];
    /*
        0 : none
        1 : infected
        2 : cured
        3 : infected again
    */
    vector<ll> status(n,0);
    priority_queue<pli,vector<pli>,greater<pli>> pque;
    auto id = [&](ll t, int type){
        return t * 3 + type;
    };
    while (k--){
        int x; cin >> x; x--;
        pque.push(pli(id(0,2),x));
    }
    int ans = 0;
    while (!pque.empty()){
        auto [tt, v] = pque.top(); pque.pop();
        ll t = tt / 3;
        int type = tt % 3;
        if (type == 0){
            status[v] = 2;
        }
        if (type == 1){
            if (status[v] == 3) continue;
            for (int u : g[v]){
                pque.push(pli(id(t,2),u));
            }
        }
        if (type == 2){
            if (status[v] >= 2) continue;
            if (status[v] == 0){
                status[v] = 1;
                pque.push(pli(id(t+s[v],1),v));
                pque.push(pli(id(t+p,0),v));
            }
            else {
                ans++;
                status[v] = 3;
            }
        }
    }
    cout << ans << endl;
}