What is the account balance of the supplier with the most parts?
account balance refers to s_acctbal; the most parts refers to max(count(ps_suppkey))
SELECT T.s_acctbal FROM ( SELECT T1.s_acctbal, COUNT(T2.ps_suppkey) AS num FROM supplier AS T1 INNER JOIN partsupp AS T2 ON T1.s_suppkey = T2.ps_suppkey GROUP BY T1.s_suppkey ) AS T ORDER BY T.num DESC LIMIT 1