public ListNode deleteDuplicates(ListNode head) {
		if (head == null){
			return null;
		}
		
		ListNode node = head;
        while (node != null &&node.next!= null){
        	if (node.val == node.next.val){
        		
        			node.next = node.next.next;
        		
        	}else{
        		node = node.next;
        	}
        		
        }
        return head;
    }