假设正读和反读都相同的字符序列为“回文”，例如，‘abba’和‘abcba’是回文，‘abcde’ 和‘ababab’则不是回文。试写一个算法判别读入的一个以‘@’为结束符的字符序列是否是“回文”-Assumptions are read and read the same sequence of characters as "palindrome", for example, Abba and abcba is a palindrome, ABCDE and ababab is