class Solution {

    public ListNode reverse(ListNode head) {
     return performReverse(null, head);
  }

  private ListNode performReverse(ListNode previous, ListNode current ){
	  if (current==null) {
	    return previous;
	  }
	    ListNode next = current.next;
	    current.next = previous;
	    return performReverse( current,next);
   }
}