LinkedList with Side nodes

LinkedList with side nodes

class SidelyLinkedList  {
    static Node head;
    static class Node {
        int item;
        Node next;
        Node side;
        Node(int item) {
            this.item =item;
            next = null;
            side = null;
        }
    }
    public static void main(String[] args) {
        SidelyLinkedList list = new SidelyLinkedList();
        list.head = new Node(51);
        list.head.next = new Node(10);
        list.head.next.next = new Node(15);
        list.head.next.next.next = new Node(18);
        list.head.next.next.next.next= new Node(21);
        list.head.side = new Node(34);
        list.head.side.side = new Node(48);
        list.head.next.side = new Node(23);
        list.head.next.side.side = new Node(67);
        list.head.next.next.side = new Node(12);
        list.head.next.next.side.side = new Node(89);
        list.head.next.next.next.side = new Node(67);
        list.head.next.next.next.side.side = new Node(92);
        list.head.next.next.next.next.side = new Node(56);
        list.head.next.next.next.next.side.side = new Node(97);
        Node res1 = list.singleList(head);
        list.printSidelyLinkedList(res1);
       }

    private Node singleList(Node node) {
        if(node.next==null){
            return node;
        }
        else{
            Node temp = node;
            Node temp1= node.next;
            while(temp.side!= null){
                temp= temp.side;
            }
            temp.side= temp1;
            node.next=temp1.next;
            return singleList(node);
        }
    }

    private void printSidelyLinkedList(Node head) {
        if(head==null){
            return;
        }
        else            {
            System.out.println(head.item +"->");
                printSidelyLinkedList(head.side);
        }
    }


}

Output:

51->
34->
48->
10->
23->
67->
15->
12->
89->
18->
67->
92->
21->
56->
97->