proc sql;
create table maxgrade as
select * from test
group by id, kind
having grade=max(grade);

create table count as
select kind, grade, count(distinct id) as num_id, count(distinct event) as num_event
from maxgrade
group by 1,2
order by 1,2;

create table allclass as
select * from
(select distinct kind from test),(select distinct grade from test)
order by kind, grade;
quit;

data wanted;
merge count allclass;
by kind grade;
if num_id=. then num_id=0;
if num_event=. then num_event=0;
run;