// AOJ 2021: Princess in Danger
// 2017.12.11 bal4u@uu

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

#define MAX 50000
typedef struct { int t, n, s, p; } QUE;
QUE que[MAX]; int qsize;

#define PARENT(i) ((i)>>1)
#define LEFT(i)   ((i)<<1)
#define RIGHT(i)  (((i)<<1)+1)

void min_heapify(int i)
{
	int l, r, min;
	QUE qt;

	l = LEFT(i), r = RIGHT(i);
	if (l < qsize && que[l].t < que[i].t) min = l; else min = i;
	if (r < qsize && que[r].t < que[min].t) min = r;
	if (min != i) {
		qt = que[i], que[i] = que[min], que[min] = qt;
		min_heapify(min);
	}
}

void deq()
{
	que[0] = que[--qsize];
	min_heapify(0);
}

void enq(int n, int t, int s, int p)
{
	int i, min;
	QUE qt;

	i = qsize++;
	que[i].n = n, que[i].t = t, que[i].s = s, que[i].p = p;
	while (i > 0 && que[min = PARENT(i)].t > que[i].t) {
		qt = que[i], que[i] = que[min], que[min] = qt;
		i = min;
	}
}

#define INF 0x07070707

typedef struct { int to[101], t[101]; } TBL;
TBL tbl[101];
int len[101];
char f[101];
char mk[101][101];

int dijkstra(int start, int goal, int m)
{
	int i, s, t, k, p, s2, t2, k2;

	memset(mk, 0, sizeof(mk));
	qsize = 0;
	enq(start, 0, m, start);
	while (qsize) {
		s = que[0].n, t = que[0].t, k = que[0].s; p = que[0].p, deq();
		if (s == goal) {
			if (t > m) t = (t << 1) - m;
			return t;
		}

		if (mk[p][s]) continue;
		mk[p][s] = 1;

		if (f[s]) k = m, p = s;
		for (i = 0; i < len[s]; i++) {
			s2 = tbl[s].to[i], t2 = t + tbl[s].t[i];
			k2 = k - tbl[s].t[i];
			if (k2 < 0 || mk[s][s2]) continue;
			enq(s2, t2, k2, p);
		}
	}
	return INF;
}

char buf[400], *p;
int getint()
{
	int n = 0;
	while (*p >= '0') n = 10*n + (*p++ & 0xf);
	p++;
	return n;
}

int main()
{
	int n, m, l, k, a, h, i, x, y, t, ans;

	while (fgets(p=buf, 60, stdin) && *p != '0') {
		n = getint(), m = getint(), l = getint();
		k = getint(), a = getint(), h = getint();

		memset(f, 0, sizeof(f));
		if (l > 0) {
			fgets(p=buf, sizeof(buf), stdin);
			while (l--) f[getint()] = 1;
		}

		memset(len, 0, sizeof(len));
		while (k--) {
			fgets(p=buf, 20, stdin);
			x = getint(), y = getint(), t = getint();
			if (t > m) continue;
			i = len[x]++, tbl[x].to[i] = y, tbl[x].t[i] = t;
			i = len[y]++, tbl[y].to[i] = x, tbl[y].t[i] = t;
		}

		ans = dijkstra(a, h, m);
		if (ans == INF) puts("Help!");
		else printf("%d\n", ans);
	}
	return 0;
}