CREATE TABLE table_2528382_5 (singers VARCHAR2, Co VARCHAR2, co_stars VARCHAR2)

How many co-singers were there when Parveen Babi co-starred?
SELECT COUNT(Co) - singers FROM table_2528382_5 WHERE co_stars = "Parveen Babi"
SELECT COUNT("Co") - "singers" FROM "table_2528382_5" WHERE "Parveen Babi" = "co_stars"