/**
 * Created by hiroqn on 13/10/12.
 */
var fs = require('fs'),
    length = fs.fstatSync(process.stdin.fd).size,
    buffer = new Buffer(length),
    bytesRead = fs.readSync(process.stdin.fd, buffer, 0, length, 0),
    input = buffer.toString('utf8', 0, bytesRead).split('\n');
main();
function dijkstra(g, s) {
  var d = [],
      use = [],
      i,
      n = g.length,
      v, u;
  for (u = 0; u < n; u++) {
    d[u] = Infinity;
    use[u] = false;
  }
  d[s] = 0;
  while (true) {
    v = -1;
    for (u = 0; u < n; u++) {
      if (!use[u] && (v === -1 || d[v] > d[u])) {
        v = u;
      }
    }
    if (v === -1) {
      break;
    }
    use[v] = true;
    for (u = 0; u < n; u++) {
      d[u] = d[u] < d[v] + g[v][u] ? d[u] : d[v] + g[v][u];
    }
  }
  return d;

}
function makeGraph(n) {
  var i, j, g;
  g = [];
  for (i = 0; i < n; i++) {
    g[i] = [];
    for (j = 0; j < n; j++) {
      g[i][j] = i === j ? 0 : Infinity;
    }
  }
  return g;
}

function main() {
  var temp,
      n, m, l, k, a, h,
      llist,
      i, j,
      edeges,
      g, g2,
      d,
      n1, n2;

  while (true) {
    temp = input.shift().split(' ');
    n = +temp[0];
    m = +temp[1];
    l = +temp[2];
    k = +temp[3];
    a = +temp[4];
    h = +temp[5];
    if (n === 0) {
      break;
    }
    if (l !== 0) {
      llist = input.shift().split(' ').map(Number);
    } else {
      input.shift();
      llist = [];
    }
    g = makeGraph(n);
    for (i = 0; i < k; i++) {
      edeges = input.shift().split(' ').map(Number);
      g[edeges[0]][edeges[1]] = g[edeges[1]][edeges[0]] = edeges[2];
    }
    g2 = makeGraph(n);
//    da = dijkstra(g, a);
    llist.push(a);
    llist.push(h);
    for (i = 0; i < l + 2; i++) {
      n1 = llist[i];
      d = dijkstra(g, n1);
      for (j = 0; j < l + 2; j++) {
        n2 = llist[j];
        if (d[n2] <= m) {
          g2[n1][n2] = g2[n2][n1] = d[n2]
        }
      }
    }
    d = dijkstra(g2, a);
    if (d[h] === Infinity) {
      console.log('Help!');
    } else {
      console.log(d[h] + Math.max(0, d[h] - m));
    }

//    console.log(d);
  }
}