import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.Scanner; /** * 【最长回文子串】 * */ public class Main { public static void main(String[] args) throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); String nextLine = br.readLine(); int maxLength = 0; for (int i = 0; i < nextLine.length(); i++) { for (int j = nextLine.length(); j > i; j--) { String substring = nextLine.substring(i, j); if (isPalindromeString(substring)) { maxLength = Math.max(maxLength, substring.length()); } } } System.out.println(maxLength); br.close(); } /** * 是否回文字符串 * * @return */ public static boolean isPalindromeString(String str) { StringBuilder sb = new StringBuilder(str); return str.equals(sb.reverse().toString()); } }