#include <bits/stdc++.h>
using namespace std;

// type {{{
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = pair<int,int>;
using vi = vector<int>;
using vll = vector<ll>;
using vvi = vector<vector<int>>;
using vvll = vector<vector<ll>>;
// }}}


// macro {{{
#define REP(i,n) for (int i=0; i<(n); ++i)
#define RREP(i,n) for (int i=(int)(n)-1; i>=0; --i)
#define FOR(i,a,n) for (int i=(a); i<(n); ++i)
#define RFOR(i,a,n) for (int i=(int)(n)-1; i>=(a); --i)

#define SZ(x) ((int)(x).size())
#define all(x) begin(x),end(x)
// }}}


// debug {{{
#define dump(x) cerr<<#x<<" = "<<(x)<<endl
#define debug(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<< endl;

template<typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    os << "[";
    REP (i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}

template<typename T, typename U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    return os << "(" << p.first << " " << p.second << ")";
}
// }}}


// chmax, chmin {{{
template<class T>
bool chmax(T& a, const T& b) {
    if (a < b) { a = b; return true; }
    return false;
}
template<class T>
bool chmin(T& a, const T& b) {
    if (b < a) { a = b; return true; }
    return false;
}
// }}}


// constants {{{
#define inf(T) (numeric_limits<T>::max() / 2)
const ll MOD = 1e9+7;
const ld EPS = 1e-9;
// }}}


template<typename T>
struct edge {
    int src, to;
    T cost;

    edge() {}
    edge(int to, T cost) : src(-1), to(to), cost(cost) {}
    edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

    friend ostream& operator<<(ostream& os, const edge& e) {
        return os << "(" << e.src << "->" << e.to << ":" << e.cost << ")";
    }
};

template<typename T>
vector<T> dijkstra(const vector<vector<edge<T>>> &g, int s) {
    const T INF = numeric_limits<T>::max();
    vector<T> d(g.size(), INF);

    using Pi = pair<T, int>;
    priority_queue<Pi, vector<Pi>, greater<Pi>> que;
    d[s] = 0;
    que.emplace(d[s], s);
    while (!que.empty()) {
        T cost;
        int v;
        tie(cost, v) = que.top();
        que.pop();
        if (d[v] < cost) continue;
        for (auto &e : g[v]) {
            T nxt = cost + e.cost;
            if (d[e.to] > nxt) {
                d[e.to] = nxt;
                que.emplace(nxt, e.to);
            }
        }
    }
    return d;
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);

    for (;;) {
        int N, M, L, K, A, H;
        cin >> N >> M >> L >> K >> A >> H;
        if (N == 0) break;
        vi freeze(L);
        REP (i, L) {
            cin >> freeze[i];
        }
        vector<vector<edge<int>>> G(N*(M+1));
        REP (i, K) {
            int u, v, t;
            cin >> u >> v >> t;
            for (int m = M; m - t >= 0; --m) {
                G[u*(M+1) + m].emplace_back(v*(M+1) + m - t, t);
                G[v*(M+1) + m].emplace_back(u*(M+1) + m - t, t);
            }
        }

        for (int v : freeze) {
            FOR (m, 0, M) {
                G[v*(M+1) + m].emplace_back(v*(M+1) + m + 1, 1);
            }
        }

        auto dist = dijkstra(G, A*(M+1) + M);
        int ans = inf(int);
        FOR (m, 0, M+1) {
            chmin(ans, dist[H*(M+1) + m]);
        }
        if (ans == inf(int)) {
            cout << "Help!" << endl;
        } else {
            cout << ans << endl;
        }
    }

    return 0;
}



Measured memory_bytes: 5328