public class DBLink {
    
    public class DBLinkList {
        private int value;
        private DBLinkList pre;
        private DBLinkList next;
        
        public int getValue() {
            return value;
        }
        public void setValue(int value) {
            this.value = value;
        }
        public DBLinkList getPre() {
            return pre;
        }
        public void setPre(DBLinkList pre) {
            this.pre = pre;
        }
        public DBLinkList getNext() {
            return next;
        }
        public void setNext(DBLinkList next) {
            this.next = next;
        }
    }
    
    public DBLinkList insertELeDbLinkList(DBLinkList pHead, int pos, int data) {
        DBLinkList temp = new DBLinkList();
        if (pos==1) {
            temp.setValue(data);
            temp.setNext(pHead);
            pHead.setPre(temp);
            return temp;
        } else {
            for (int i=1; i<pos-1;i++) {
                temp = pHead;
                if (temp.getNext()==null) {
                    return null;
                }
                pHead = temp.getNext();
            }
            DBLinkList insertLink = new DBLinkList();
            insertLink.setValue(data);
            insertLink.setPre(temp);
            insertLink.setNext(pHead);
            return insertLink;
        }
    }

    public static void main (String args[]) {

    }
}