function clean(bot, target, cleaners) {
  return grid.filter(c => c.id === target.id && !c.reserved).reduce((best, n) => {
    const distance = bot.distance(pos);
    const closest = Math.min(...cleaners.map(b => b.distance(pos)));
    const wrongness = distance - closest;
    if (wrongness < best.wrongness || (wrongness === best.wrongness && (distance < best.distance))) {
      best.arr = [];
    }
  }, {arr: [], wrongness: Infinity, distance: Infinity});
  return grid.reduce((best, c, i) => {
    const pos = XY.fromIndex(i);
    const closest = Math.min(...cleaners.map(b => b.distance(pos)));
    const distance = bot.distance(pos);
    const wrongness = distance - closest;
    const distanceFromTarget = target.distance(pos);
    if (c.id === target.id && !c.reserved && (wrongness < best.wrongness || (wrongness === best.wrongness && (distance < best.distance || (distance === best.distance && distanceFromTarget > best.distanceFromTarget))))) {
      return {wrongness: wrongness, distance: distance, distanceFromTarget: distanceFromTarget, pos: pos};
    } else {
      return best;
    }
  }, {wrongness: Infinity, distance: Infinity, distanceFromTarget: -Infinity, pos: bot}).pos;
}
function roam(bot) {
  const dangerousBots = bots.filter(b => !b.member && separation(b.id, bot.id) !== 2);
  return grid.reduce((best, c, i) => {
    const pos = XY.fromIndex(i);
    const val = value(c.id, bot);
    const distance = bot.distance(pos);
    const comfyness = pos.getNeighbors().reduce((sum, next) => sum + (value(at(next).id, bot) <= 2), 0);
    const closestBotDist = Math.min(...dangerousBots.map(b => b.distance(pos)));
    if (val >= 4 && !swarm.find(m => m.id === c.id) && !c.bot && (distance < best.distance || (distance === best.distance && (val > best.val || (val === best.val && (comfyness > best.comfyness || (comfyness === best.comfyness && closestBotDist > best.closestBotDist))))))) {
      return {distance: distance, val: val, comfyness: comfyness, closestBotDist: closestBotDist, pos: pos};
    } else {
      return best;
    }
  }, {distance: Infinity, val: -Infinity, comfyness: -Infinity, closestBotDist: -Infinity, pos: bot}).pos;
}