CREATE TABLE table_60797 ("Battle" CLOB, "Date" CLOB, "Bulgarian Commander" CLOB, "Byzantine Commander" CLOB, "Result" CLOB)

What is the Byzantine Commander with a Bulgarian Victory at the Siege of Lovech?
SELECT "Byzantine Commander" FROM table_60797 WHERE "Result" = 'bulgarian victory' AND "Battle" = 'siege of lovech'
SELECT "Byzantine Commander" FROM "table_60797" WHERE "Battle" = 'siege of lovech' AND "Result" = 'bulgarian victory'