Table schema:
CREATE TABLE table_name_50 (original_amendments_cosponsored INTEGER, all_bills_sponsored VARCHAR, bill_support_withdrawn VARCHAR)

Question: How many original bills amendments cosponsored lower than 64,with the bill support withdrawn lower than 0?
SQL: SELECT MIN(original_amendments_cosponsored) FROM table_name_50 WHERE all_bills_sponsored < 64 AND bill_support_withdrawn < 0