(define (longest-word sym)
(define convert
(lambda (l)
(if(null? l)
'()
(append (convert (cdr l))(list(symbol->string (car l)))))))
(define (longest l str)
(if(null? l)
str
(if(> (string-length (car l)) (string-length str))
(longest (cdr l) (car l))
(longest (cdr l) str))))
(longest (convert sym) ""))
(longest-word '(the terms quote or quotation when used as a noun may have a meaning of a quotation mark which is a punctuation mark used to indicate that the enclosed words were spoken by someone))