package main
import . "nc_tools"
/*
 * type ListNode struct{
 *   Val int
 *   Next *ListNode
 * }
 */

/**
  * 
  * @param head ListNode类 
  * @return ListNode类
*/
func deleteDuplicates( head *ListNode ) *ListNode {
    // write code here
    cur := head
    for cur != nil {
        next := cur.Next
        for next != nil && cur.Val == next.Val {
            next = next.Next
            cur.Next = next
        }
        cur = next
    }
    return head
}