import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
     *
     * 反转字符串
     * @param str string字符串
     * @return string字符串
     */
    public String solve (String str) {
        // write code here
        StringBuilder reBuilder = new StringBuilder();
        for (int i = str.length() - 1; i >= 0; i--) {
            reBuilder.append(str.charAt(i));
        }

        return reBuilder.toString();
    }
}