SELECT T3.balance FROM accounts AS T1 JOIN checking AS T2 ON T1.custid  =  T2.custid JOIN savings AS T3 ON T1.custid  =  T3.custid ORDER BY T2.balance DESC LIMIT 1
What is the savings balance of the account belonging to the customer with the highest checking balance?
[Schema (values) (types)]: | small_bank_1 |  ACCOUNTS : custid (text) , name (number) | SAVINGS : custid (text) , balance (number) | CHECKING : custid (text) , balance (number);