SQL & PL/SQL :: Cursor For Loop Updates Only One Record?

I have a table of 3 columns:

SQL> show user
USER is "ANDREY"
SQL>
SQL>
SQL>
SQL> --create the table:

[code]...

I insert rows into it:

SQL> --fill it with data:
SQL>
SQL> insert into a(key1 , key2) values (1 , 1);
1 row created.
SQL> insert into a(key1 , key2) values (1 , 5);

[code]...

i want to perform a logic by which:for every distinct value of key1 - values of key2 will be checked in all records holding that particular key1 value, and update the key3 field to 'inactive' where the key2 value for that particular key1 is the highest in number.

i've found out that i could do it by an SQL statement:

update a
set key3 = 'inactive'
where key2 = (
select max(key2)
from a a2 where a2.key1=a.key1
);

however I wanted to use the cursor to "load" the max key2 values FOR EACH distinct key1 value exists in the table,and do the same thing as the update statement above WITH A CURSOR,So tried and wrote the following:

SQL> create or replace procedure proc1
2 IS
3
4
5 var1 a.key1%type;

[code]...

unfortunately, it works only for one row, and i don't understand what's wrong, I executed, and checked what has changed:

SQL> exec proc1;
PL/SQL procedure successfully completed.
SQL> select * from a;
KEY1 KEY2 KEY3
---------- ---------- ----------
1 1 active
1 5 incative
2 24 active
2 21 active

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