How to create a package in oracle?

Question

Oracle

CREATE OR REPLACE PACKAGE common is 
  FUNCTION kolvo(otdel in varchar2) return number
  IS KOLV_SOTR NUMBER;
  BEGIN
    SELECT COUNT(*)INTO KOLV_SOTR FROM (SELECT * FROM SOTR_1 a, OTDEL b
    WHERE otdel=b.NAME_DEPARTMENT and a.KOD_DEPARTMENT = b.KOD_DEPARTMENT);
  end kolvo;
  procedure perefod(my_shipher sotr_1.shipher%type, my_name_dol list_dol.name_dol%type)
  is
  begin
  update sotr_1 set kod_dol = (select kod_dol from list_dol where name_dol = my_name_dol)
  where my_shipher = sotr_1.shipher;
  end perefod;
end;

When creating packages, it displays the following. message