Get records which doesn't have duplicate records
Assuming you just want to avoid the records that're bold:

Setup:

create table simplequestion 
(
 p number,
 c number  
);

insert into simplequestion values (23442242,3455);

insert into simplequestion values (53453453,3454);

insert into simplequestion values (23442242,3455);

insert into simplequestion values (23442242,4567);

insert into simplequestion values (23442242,4667);

insert into simplequestion values (53453453,5656);

insert into simplequestion values (53535354,3543);

insert into simplequestion values (34543545,4354);


Query:

select p,c,count(*)
from simplequestion
group by p,c
having count(*)=1;