import java.util.*;

public class WarshallFloyd {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		while(true) {
			int n = sc.nextInt(), m = sc.nextInt(),
			l = sc.nextInt(), k = sc.nextInt(), 
			a = sc.nextInt(), h = sc.nextInt();
			if(n == 0) break;
			int[][] AM = new int[n][n];
			for(int[] tmp : AM) Arrays.fill(tmp, 1 << 28);
			Set<Integer> freezers = new HashSet<Integer>();
			freezers.add(a); freezers.add(h);
			for(int i = 0; i < l; i++) 
				freezers.add(sc.nextInt());
			for(int i = 0; i < k; i++) {
				int src = sc.nextInt(), des = sc.nextInt(), cost = sc.nextInt();
				AM[src][des] = AM[des][src] = cost;
			}
			WarshallFloyd(AM, n);
			for(int i = 0; i < n; i++)
				for(int j = 0; j < n; j++)
					if(AM[i][j] > m || 
							!freezers.contains(i) || 
							!freezers.contains(j))
						AM[i][j] = 1 << 28;
			WarshallFloyd(AM, n);
			if(AM[a][h] == 1 << 28) {
				System.out.println("Help!");
			} else {
				System.out.println(AM[a][h] + Math.max(0, AM[a][h] - m));
			}
		}
	}
	static void WarshallFloyd(int[][] AM, int n) {
		for(int k = 0; k < n; k++)
			for(int i = 0; i < n; i++)
				for(int j = 0; j < n; j++)
					AM[i][j] = Math.min(AM[i][j], AM[i][k] + AM[k][j]);
	}
}