#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, k, m, p; cin >> n >> k >> m >> p;
	vector<vector<int>>to(n);
	rep(i, m) {
		int u, v; cin >> u >> v;
		u--, v--;
		to[u].push_back(v);
		to[v].push_back(u);
	}
	vector<int>s(n);
	rep(i, n)cin >> s[i];
	priority_queue<P, vector<P>, greater<P>> pq;
	vector<int>day(n, -1);// 感染日
	rep(i, k) {
		int x; cin >> x; x--;
		day[x] = 0;
		pq.push({ day[x] + s[x],x });// ばらまく日
	}
	vector <bool> ng(n);
	int ans = 0;
	while (!pq.empty()) {
		int d = pq.top().first;
		vector<int>v;
		//同じ日
		while (!pq.empty() && d == pq.top().first) {
			int idx = pq.top().second;
			pq.pop();
			if (ng[idx])continue;
			for (auto ni : to[idx]) {
				if (-1 == day[ni]) {// 未感染
					day[ni] = d;
					pq.push({ day[ni] + s[ni],ni });
				}
				else {
					if (d < day[ni] + p && !ng[ni]) {
						v.push_back(ni);
						//ng[ni] = true;
					}
				}
			}
		}
		for (int i : v) {
			ans += !ng[i];
			ng[i] = true;
		}
	}// 同じ日二回も含む
//	rep(i, n)if (ng[i])ans++;
	cout << ans << endl;
	return 0;
}