To avoid ambiguity, we have updated the checker log message for Problem B. Previously, when the checker detected that the permutation did not satisfy the problem requirements, it would output “The permutation is invalid.” However, the output in such cases is still a valid permutation; it simply does not meet the conditions specified in the problem. Therefore, we have revised the message to the more accurate “The permutation is not good.” This change does not affect the actual judging behavior of the checker. It is only intended to improve the clarity of the checker log messages.