#include <iostream>
#include <fstream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <cstring>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <algorithm>
using namespace std;
 
#define REP(i,n) for(int i=0; i<n; ++i)
#define FOR(i,a,b) for(int i=a; i<=b; ++i)
#define FORR(i,a,b) for (int i=a; i>=b; --i)
#define pi acos(-1.0)
 
typedef long long ll;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef vector<VI> VVI;
typedef pair<int,int> P;
typedef pair<ll,ll> PL;

const int INF = 1e9;

int main(){
	int n, m, l, k, a, h;
	while (cin >> n >> m >> l >> k >> a >> h  && n){
		VVI d(n, VI(n, INF));
		REP(i,n) d[i][i] = 0;
		VI hos;
		hos.push_back(a);
		hos.push_back(h);
		while (l--){
			int x;
			cin >> x;
			hos.push_back(x);
		}
		while (k--){
			int x, y, z;
			cin >> x >> y >> z;
			d[x][y] = z;
			d[y][x] = z;
		}
		REP(i,n) REP(j,n) REP(k,n){
			d[j][k] = min(d[j][k], d[j][i]+d[i][k]);
		}
		l = hos.size();
		VVI dh(l, VI(l,INF));
		REP(i,l) dh[i][i] = 0;
		REP(i,l) REP(j,l){
			if (d[hos[i]][hos[j]] <= m) dh[i][j] = d[hos[i]][hos[j]];
		}
		REP(i,l) REP(j,l) REP(k,l){
			dh[j][k] = min(dh[j][k], dh[j][i]+dh[i][k]);
		}
		int ans = dh[0][1];
		if (dh[0][1] > m) ans += dh[0][1] - m;
		if (dh[0][1] == INF) cout << "Help!" << endl;
		else cout << ans << endl;
	}

    return 0;
}