#include <iostream>
#include <vector>
#include <map>
#include <algorithm>

using namespace std;
typedef pair<int,int> pii;
vector<int> G[100010];
int s[100010],c[100010];
bool cure[100010],iru[100010];
int main(){
    int i,n,k,m,p; cin >> n >> k >> m >> p;
    for(i=0;i<m;i++){
        int u,v; cin >> u >> v; u--; v--;
        G[u].push_back(v); G[v].push_back(u);
    }
    for(i=0;i<n;i++){
        cure[i] = false; iru[i] = true;
    }
    map<int,vector<pair<int,int>>> ms;
    for(i=0;i<n;i++) cin >> s[i];
    for(i=0;i<k;i++){
        int x; cin >> x; x--;
        ms[p].push_back({-1,x});
        ms[s[x]].push_back({1,x});
        c[x] = 1;
    }
    while(ms.size()){
        auto x = *ms.begin();
        ms.erase(x.first);
        vector<pair<int,int>> v = x.second;
        sort(v.begin(),v.end());
        vector<int> del;
        for(auto pp:v){
            if(pp.first==-1){
                cure[pp.second] = true;
            }else{
                if(!iru[pp.second]) continue;
                for(int u:G[pp.second]){
                    if(!cure[u]){
                        if(!c[u]){
                            c[u] = 1;
                            ms[x.first + p].push_back({-1,u});
                            ms[x.first + s[u]].push_back({1,u});
                        }else{
                            del.push_back(u);
                        }
                    }
                }
            }
        }
        for(int u:del){
            iru[u] = false;
        }
    }
    int ans = 0;
    for(i=0;i<n;i++){
        if(!iru[i]) ans++;
    }
    cout << ans << "\n";
    // for(i=0;i<n;i++) cout << iru[i];
    // cout << endl;
}