input: A (B C D)

A 
| (B C D
| )


input: A (B C D) (E F G)

A 
| (B C D
| ) 
| (E F G
| )


input: A B (C (D E) (F G)) (H I)

A B 
| (C 
| | (D E
| | ) 
| | (F G
| | )
| ) 
| (H I
| )