create a new variable with same value

[ari]

Have:
ID	v1	v2	v3
1	-3	a	a
1	-2	b	b
1	-1	c	b
1	1	d	b
2	-20	a	a
2	-6	b	b
2	-3	c	b
2	-2	d	b
3	1	a	a

ID	v1	v2	v5
1	-3	a	a
1	-2	b	a
1	-1	c	a
1	1	d	a
2	-20	a	a
2	-6	b	a
2	-3	c	a
2	-2	d	a
3	1	a	a

I am wondering how to create a new variable  v5, if any of the values of v3  per subject are 'a' then v5 should be populated with the same value 'a' (v5 contains only a in output).?

[Kurt_Bremser]

proc sort
  data=have (keep=id v3 where=(v3 = 'a'))
  out=help (rename=(v3=v5))
  nodupkey
;
by id;
run;

data want;
merge
  have (drop=v3)
  help
;
by id;
run;

Just one of the many possible solutions

[Jagadishkatam]

data want;
do until(first.id);
set have;
by id;
v5=v2;
end;
do until(first.id);
set have;
by id;
output;
end;
run;

[Ksharp]

data have;
infile cards expandtabs truncover;
input ID 	v1	v2 $	v3 $;
cards;
1	-3	a	a
1	-2	b	b
1	-1	c	b
1	1	d	b
2	-20	a	a
2	-6	b	b
2	-3	c	b
2	-2	d	b
3	1	a	a
;
run;
proc sql;
select *,case when(sum(v3='a') ne 0) then 'a' else ' ' end as v5
 from have
  group by id;
quit;