The total score of the first five exams is 428 points, and the average score of the sixth to ninth exams is 1.4 points higher than the average score of the first five exams. Now it is time to take the tenth test. If the average score of the last five tests is higher than the average score of all ten tests, what is the minimum score for the tenth test? (Note: The scores of each test are integers)
前五次考试的总分是428分，第六次至第九次的平均分比前五次平均分多1.4分．现在要进行第十次考试，要使后五次平均分高于所有十次的平均分，那么第十次至少要考多少分．(注：每次考试的分数都是整数)
<result>81</result>