What is the error in this trigger

Question

create or replace trigger tt1
after insert on EXERCISE2_T
referencing new as new
for each row
declare
v_excd EXERCISE2_T.EX_CD%type:=(CASE EX_CD
    WHEN 'X' THEN 'Extracted';
    WHEN 'F' THEN 'Failed';
    WHEN 'S' THEN 'Skipped';
    WHEN 'C' THEN 'Cancelled';
    ELSE 'no');
begin
insert into DWH_DEX2_RD_T(DK_EX2,
EX2_CD,
EX2_NM) values(:new.EX_ID,:new.EX_CD,v_excd);
end;error
3/30 PLS-00103: Encountered the symbol ";" when expecting one of the following:
* & = - + < / > at else end in is mod remainder not rem when
<an exponent (**)> <> or != or ~= >= <= <> and or like LIKE2_
LIKE4_ LIKEC_ between || multiset member SUBMULTISET_

Answer 1

create or replace trigger tt1
  after insert
  on exercise2_t
  referencing new as new
  for each row
declare
  v_excd                        exercise2_t.ex_cd%type
    := case ex_cd
    when 'X'
      then 'Extracted'
    when 'F'
      then 'Failed'
    when 'S'
      then 'Skipped'
    when 'C'
      then 'Cancelled'
    else 'no'
  end;
begin
  insert into dwh_dex2_rd_t
                dk_ex2, ex2_cd, ex2_nm )
       values (
                :new.ex_id, :new.ex_cd, v_excd );
end;
/In other words: the semi-columns and the case-END.