CREATE TABLE table_11639 ("Route Name" CLOB, "Direction" CLOB, "Termini" CLOB, "Junctions" CLOB, "Length" CLOB, "Population Area" CLOB, "Remarks" CLOB)

What is the length of the highway with remarks that it was replaced by lp 20?
SELECT "Length" FROM table_11639 WHERE "Remarks" = 'replaced by lp 20'
SELECT "Length" FROM "table_11639" WHERE "Remarks" = 'replaced by lp 20'