#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <atcoder/modint>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;

int main(){
    int N, K, M, P; cin >> N >> K >> M >> P;
    vector<vector<int>> adj(N);
    rep(i,M){
        int u,v; cin >> u >> v; u--; v--;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    vector<int> S(N); rep(i,N) cin >> S[i];
    using F = pair<int, pair<int,int>>;
    priority_queue<F, vector<F>, greater<F>> que;
    vector<int> hit(N);
    vector<int> spr(N);
    vector<int> rem(N);
    vector<int> rec(N);
    int hitcount = 0;
    rep(i,K){
        int x; cin >> x; x--;
        hit[x] = 1;
        hitcount++;
        que.push({ S[x], {1,x} });
        que.push({ P, {0,x} });
    }
    while(que.size()){
        //if(hitcount == 0) break;
        auto [t,oc] = que.top(); que.pop();
        auto [w,x] = oc;
        if(rem[x]) continue;
        if(w == 0){
            rec[x] = 1;
            hitcount -= hit[x]; hit[x] = 0;
        }
        else if(w == 1){
            for(int y : adj[x]) if(rem[y] == 0 && rec[y] == 0){
                if(hit[y]){ que.push({ t, {2,y} }); continue; }
                hit[y] = 1;
                hitcount++;
                que.push({ t + S[y], {1,y} });
                que.push({ t + P, {0,y} });
            }
        }
        else{
            rem[x] = 1;
            hitcount -= hit[x];
            hit[x] = 0;
        }
    }
    int ans = 0;
    rep(i,N) ans += rem[i];
    cout << ans << endl;
    return 0;
}

struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;