#!/usr/bin/env ruby
require 'json'

a = []
while line=gets
  a << line.to_i
end
stringify(JSON.generate(a))		# jsだと stringify()

STDERR.print "JSONの配列: "
json = gets.chomp		# 読み取る
array = JSON.parse(json)	# 文字列をJSONの値に変換
for (var x of array) {...}
  if (x%2 == 0)
    print("%d\n", x)		# Rhino jsだと print()
  end
end