题解 | #反序输出#

import java.util.*;

// 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);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNext()) { // 注意 while 处理多个 case
            String str = in.next();
            String before = "";
            String after = "";
            for (int i = str.length() - 1, j = str.length() / 2 - 1;
                    i > str.length() / 2 - 1; i--, j--) {
                before = before + str.charAt(i);
                after = after + str.charAt(j);
            }
            if (!(str.length() % 2 == 0)) {
                before = before + str.charAt(str.length() / 2 - 1);
            }

            System.out.println(before + after);
        }
    }
}