Project Euler

[ホーム](https://redmine.noppi.jp) - [[Wiki|Project Euler]]

# [[Problem 2]]

```scheme

#!r6rs

#!chezscheme

(import (chezscheme))

(define answer-2

  (let loop ((first 0) (second 1) (result 0))

    (let ((next (+ first second)))

      (cond

        [(< 4000000 next) result]

        [(even? next)

         (loop second next (+ result next))]

        [else (loop second next result)]))))

(printf "2: ~D~%" answer-2)

```