#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
using namespace std;
using ll = long long;
using P = pair<int, int>;
constexpr ll MOD = 998244353;

int main(){
    int n, m, k, p; cin >> n >> k >> m >> p;
    vector<vector<int>> G(n);
    for(int i = 0; i < m; i++){
        int u, v; cin >> u >> v;
        u--; v--;
        G[u].emplace_back(v);
        G[v].emplace_back(u);
    }
    vector<int> s(n);
    for(auto &it: s) cin >> it;
    vector<int> x(k);
    for(auto &it: x){
        cin >> it;
        it--;
    }

    const int lim = 120000000;
    vector<map<int, vector<int>>> events(2);
    vector<int> states(n, 0);
    vector<int> cnt(n, 0);

    int ans = 0;
    priority_queue<int, vector<int>, greater<int>> days;
    for(const auto &it: x){
        events[1][s[it]].emplace_back(it);
        days.emplace(s[it]);
        events[0][p].emplace_back(it);
        days.emplace(p);
        cnt[it]++;
        states[it] = 1;
    }
    set<int> past;
    while(!days.empty()){
        const int day = days.top(); days.pop();
        if(past.count(day) == 1) continue;
        past.emplace(day);
        if(events[0].count(day) == 1){
            for(const auto &it: events[0][day]){
                if(states[it] == 3) continue;
                states[it] = 2;
            }
        }
        if(events[1].count(day) == 1){
            for(const auto &it: events[1][day]){
                if(states[it] == 3) continue;
                for(const auto &nex: G[it]){
                    if(2 <= states[nex]) continue;
                    cnt[nex]++;
                    if(cnt[nex] == 1){
                        events[1][day+s[nex]].emplace_back(nex);
                        days.emplace(day+s[nex]);
                        events[0][day+p].emplace_back(nex);
                        days.emplace(day+p);
                        states[nex] = 1;
                    }else{
                        states[nex] = 3;
                        ans++;
                    }
                }
            }
        }
    }
    cout << ans << endl;
    return 0;
}