Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE loan (cust_id VARCHAR, amount INTEGER)
TABLE: CREATE TABLE customer (cust_name VARCHAR, cust_id VARCHAR)

### Question ###
Find the name of customer who has the highest amount of loans.

### Accurate SQL ###

SELECT T1.cust_name FROM customer AS T1 JOIN loan AS T2 ON T1.cust_id = T2.cust_id GROUP BY T1.cust_name ORDER BY SUM(T2.amount) DESC LIMIT 1