CREATE TABLE table_69813 ("Country" CLOB, "Chart" CLOB, "Period" CLOB, "Peak position" CLOB, "Sales" CLOB)

Name the period for south korea with peak position of #1
SELECT "Period" FROM table_69813 WHERE "Country" = 'south korea' AND "Peak position" = '#1'
SELECT "Period" FROM "table_69813" WHERE "Country" = 'south korea' AND "Peak position" = '#1'