PL/SQL :: Creation Of A Table After Checking Whether It Is Existing

declare
vnum number;
vname varchar2(50):='t1';
begin
begin
select count(*) into vnum from dba_tables where table_name=vname;
dbms_output.put_line('table count '||vnum);
exception

when others then

vnum := 0;
end;
begin
if vnum>0 then
execute immediate 'drop table '||vname;
dbms_output.put_line('table dropped');
end if;
exception

when others then

dbms_output.put_line('table does not exists');
end;
execute immediate 'create table '||vname ||' ( n number)';
dbms_output.put_line('table created');
end;