#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int N,K,M,P;
vector<int> E[101010];
int S[101010];
int D[101010];
int fix[101010];

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>K>>M>>P;
	FOR(i,M) {
		cin>>x>>y;
		E[x-1].push_back(y-1);
		E[y-1].push_back(x-1);
	}
	FOR(i,N) cin>>S[i];
	FOR(i,N) D[i]=1<<30;
	priority_queue<pair<int,int>> Q;
	FOR(i,K) {
		cin>>x;
		x--;
		D[x]=0;
		Q.push({-S[x],x});
	}
	MINUS(fix);
	int ret=0;
	while(Q.size()) {
		int cd=-Q.top().first;
		int cur=Q.top().second;
		Q.pop();
		if(fix[cur]!=-1&&fix[cur]<cd) continue;
		FORR(e,E[cur]) {
			if(D[e]==1<<30) {
				D[e]=cd;
				Q.push({-(cd+S[e]),e});
			}
			else if(cd<D[e]+P&&fix[e]==-1) {
				ret++;
				D[e]=-1;
				fix[e]=cd;
			}
		}
		
	}
	cout<<ret<<endl;
	
		
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}