function mergeLists(head1, head2) {
  let head, list = getItems(head2).split(',')
  .concat(getItems(head1).split(','))
  .sort((a,b) => b-a)
	
  for(let i =0; i<list.length; i++ ){
    let res = new SinglyLinkedListNode(list[i])
    res.next = head
    head = res
  }
   return head
}

function getItems(item){
  let list = []
  Object.entries(item).forEach((a,b) =>{
    if(typeof(a[1]) == 'object' && a[1] != null) list.push(getItems(a[1]))
    if(typeof(a[1]) == 'number') list.push(a[1])
  })
  return list.toString()
}