def isPalindrome(n)
  numString = n.to_s
  for i in 0..(numString.length-1)/2
    if !(numString[i] == numString[numString.length-1-i])
      return false
    end
  end
  return true
end

def productsOfThreeDigits
  products = []
  for i in 100..999
    for j in 100..999
      products << i*j
    end
  end
  products
end

palindromes = []
for i in productsOfThreeDigits
  if isPalindrome(i)
    palindromes << i
  end
end

puts palindromes.sort