Select single with max , get record from 2 tables

Hello professionals,

i have two tables like this:

I want to write Sql query to get the record with the MAX begda.

(25/10/2022)

single record only from all tables.

I tried to do something like this

  SELECT
  MAX( BEGDA )
    massn
    pernr
   FROM  (
    SELECT pernr begda massn
    FROM pa0000
       UNION ALL
       SELECT pernr begda massn FROM pa0302) AS a
    INTO CORRESPONDING FIELDS OF TABLE gt_pa0000
    UP TO 1 ROWS.

and i tried with CASE:

  SELECT a~pernr
         a~massn
         a~begda
      FROM pa0000 as a LEFT JOIN pa0302 AS b  ON a~pernr = b~pernr
         CASE a~begda > b~begda THEN a~begda
         ELSE  a~begda < b~begda THEN b~begda END.

:it's not work.

please help me :)

thanks.