(let ( (From (read (current-input-port))) (To (read (current-input-port))) ) (let loop((i From)) (begin (when (or (= (modulo i 3) 0 ) (= (CheckThree i) #t)) (begin (display i) (newline))) (unless (= i To) (loop (+ i 1))) ) ) ) (define (CheckThree x) (let loop((i x)) (if (= (modulo i 10) 3) #t (if (> i 3) (loop (inexact->exact (floor (/ i 10)))) #f))))