#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAXN 30000
#define MAXM 500000
#define MAXK 200

typedef struct EDGE
{
    int From;
    int To;
    int Length;
}
EDGE;

typedef struct FOL
{
    int To;
    int Length;
}
FOL;

EDGE Edge[MAXM];

int Degree[MAXN];
int CurIndex[MAXN];
FOL Fol[MAXM];
int iFol[MAXN];

int Base[MAXN];

int List[MAXK][MAXN];
int nList[MAXK];

int Dist[MAXN];

int main()
{
    while(1)
    {
	int n, m, a, k;
	scanf("%d%d%d%d", &n, &m, &a, &k);
	k--;
	
	if(!(n))
	{
	    break;
	}
	
	memset(Degree, 0, sizeof(Degree));
	for(int i = 0; i < m; i++)
	{
	    scanf("%d%d%d", &(Edge[i].From), &(Edge[i].To), &(Edge[i].Length));
	    Edge[i].From--;
	    Edge[i].To--;
	    
	    Degree[Edge[i].From]++;
	    Degree[Edge[i].To]++;
	}
	
	iFol[0] = 0;
	for(int i = 0; i < n; i++)
	{
	    iFol[i + 1] = iFol[i] + Degree[i];
	}
	
	memset(CurIndex, 0, sizeof(CurIndex));
	for(int i = 0; i < m; i++)
	{
	    int e = Edge[i].From;
	    Fol[iFol[e] + CurIndex[e]].To = Edge[i].To;
	    Fol[iFol[e] + CurIndex[e]].Length = Edge[i].Length;
	    CurIndex[e]++;
	    
	    e = Edge[i].To;
	    Fol[iFol[e] + CurIndex[e]].To = Edge[i].From;
	    Fol[iFol[e] + CurIndex[e]].Length = Edge[i].Length;
	    CurIndex[e]++;
	}
	
	for(int i = 0; i < a; i++)
	{
	    scanf("%d", Base + i);
	    Base[i]--;
	}
	
	/*printf("Bases\n");
	for(int i = 0; i < a; i++)
	{
	    printf("%d ", Base[i]);
	}
	printf("\n");
	
	for(int i = 0; i < n; i++)
	{
	    printf("Followers of %d: ", i + 1);
	    for(int j = iFol[i]; j < iFol[i + 1]; j++)
	    {
		printf("%d ", Fol[j].To + 1);
	    }
	    
	    printf("\n");
	}*/
	
	for(int i = 0; i < n; i++)
	{
	    Dist[i] = 1 << 30;
	}
	
	int nSafe = n;
	for(int i = 0; i < a; i++)
	{
	    if(Dist[Base[i]] == 1 << 30)
	    {
		nSafe--;
	    }
	    
	    List[0][nList[0]++] = Base[i];
	    Dist[Base[i]] = 0;
	    
	    for(int cdist = 0; cdist <= k;)
	    {
		if(!(nList[cdist]))
		{
		    cdist++;
		    continue;
		}
		
		int cur = List[cdist][--nList[cdist]];
		for(int j = iFol[cur]; j < iFol[cur + 1]; j++)
		{
		    //printf("!\n");
		    int t = Fol[j].To;
		    int l = Fol[j].Length;
		    
		    //printf("%d -> %d examined\n", cur + 1, t + 1);
		    
		    if(Dist[cur] + l > k)
		    {
			continue;
		    }
		    
		    if(Dist[t] > Dist[cur] + l)
		    {
			if(Dist[t] == 1 << 30)
			{
			    nSafe--;
			}
			
			Dist[t] = Dist[cur] + l;
			List[Dist[t]][nList[Dist[t]]++] = t;
			
			//printf("Vertex %d reached by %d\n", t + 1, Dist[t]);
			//printf("cdist; nList[1]: %d, %d\n", cdist, nList[1]);
		    }
		}
	    }
	    
	    printf("%d\n", nSafe);
	}
	
	printf("\n");
    }
    
    return 0;
}