//Solution to Viral Hotel problem by writer: BortiK

#include<bits/stdc++.h>

using namespace std;

int main(){
    int N, K, M, P; 
    cin >> N >> K >> M >> P;
    vector<vector<int>> adj(N);
    for(int i = 0; i < M; i++){
        int u,v; cin >> u >> v;
        u--;v--;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    vector<int> s(N);
    for(int i = 0; i < N; i++){
        cin >> s[i];
    }

    priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> todo;
    vector<int> infected(N, -1);
    for(int i = 0; i < K; i++){
        int x; cin >> x;
        x--;
        todo.push(make_pair(s[x],x));
        infected[x] = 0;
    }

    vector<bool> quar(N, false);
    int answer = 0;
    
    while(!todo.empty()){
        pair<int,int> x = todo.top();
        todo.pop();
        if(quar[x.second]) continue;
        for(int u: adj[x.second]){
            if(infected[u] == -1){
                infected[u] = x.first;
                todo.push(make_pair(x.first+s[u], u));
            } else {
                if(infected[u]+P > x.first){
                    if(!quar[u]){
                        answer++;
                        quar[u] = true;                        
                    }
                }
            }
        }
    }

    cout << answer;
}