(define (divides? a b)
(= (remainder a b) 0))

(define (leap-year? c)
    (cond   ((divides? c 100) #f)
        ((divides? c 400) #t)
            ((divides? c 4) #t)
        (else #f)
    )
)

(define (leap-year-logical? c)
 (and (or (divides? c 4) (divides? c 400)) (not (divides? c 100)))
)