题解 | #字符串反转#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String sbf ="";
        String a = in.nextLine();
        for (int i = a.length()-1;i>=0;i--){
            if (a.charAt(i)<='z' && a.charAt(i)>='a'){
                String substring = a.substring(i, i + 1);
                sbf+=substring;
            }
        }
        System.out.println(sbf);
    }
    
}