#| BEGIN (Введите свое решение) |#
(define (enumerate-interval low high)
  (if (> low high)
      '()
      (cons low 
            (enumerate-interval 
             (+ low 1) 
             high))))
(define (accumulate op initial sequence)
  (if (null? sequence)
      initial
      (op (car sequence)
          (accumulate op 
                      initial 
                      (cdr sequence)))))
(define (flatmap proc seq)
  (accumulate append '() (map proc seq)))
(define (unique-pairs n)
  (flatmap (lambda (i)
             (map (lambda (j)
                    (list i j))
                  (enumerate-interval 1 (- i 1))))
             (enumerate-interval 1 n)))
#| END |#