判斷迴文串，反轉一下，然後判斷一下就可以了

import java.lang.*;
import java.util.*;

public class Main{

    public static void main(String[] args){

        Scanner cin = new Scanner(System.in);

        String str = cin.next();

        StringBuffer ss = new StringBuffer(str);

        ss.reverse();

        int flag = 0;

        for(int i = 0;i < str.length();i++) {

            if(str.charAt(i) != ss.charAt(i)) {

                flag = 1;

                break;

            }

        }

        System.out.println(str.length());

        if(flag == 1)

            System.out.println("N");

        else

            System.out.println("Y");

    }

}