CF1808A.Lucky Numbers

Olympus City recently launched the production of personal starships. Now everyone on Mars can buy one and fly to other planets inexpensively.

Each starship has a number —some positive integer $x$. Let's define the luckiness of a number $x$ as the difference between the largest and smallest digits of that number. For example, $142857$ has $8$ as its largest digit and $1$ as its smallest digit, so its luckiness is $8-1=7$. And the number $111$ has all digits equal to $1$, so its luckiness is zero.

Hateehc is a famous Martian blogger who often flies to different corners of the solar system. To release interesting videos even faster, he decided to buy himself a starship. When he came to the store, he saw starships with numbers from $l$ to $r$ inclusively. While in the store, Hateehc wanted to find a starship with the luckiest number.

Since there are a lot of starships in the store, and Hateehc can't program, you have to help the blogger and write a program that answers his question.

奥林匹斯城最近启动了个人星际飞船的生产。如今，火星上的每个人都可以购买一艘，以低廉的价格飞往其他星球。

每艘星际飞船都有一个编号——某个正整数 $x$。我们定义一个数 $x$ 的“幸运值”为该数各位数字中最大数字与最小数字之差。例如，$142857$ 的最大数字是 $8$，最小数字是 $1$，因此其幸运值为 $8-1=7$；而数字 $111$ 的所有数字均为 $1$，故其幸运值为 $0$。

Hateehc 是一位著名的火星博主，经常飞往太阳系各个角落。为了更快地发布有趣的视频，他决定为自己购置一艘星际飞船。当他来到商店时，发现店内陈列的飞船编号范围为从 $l$ 到 $r$（含端点）。在店内，Hateehc 希望找到幸运值最大的那艘飞船。

由于店内飞船数量众多，而 Hateehc 又不会编程，因此你需要帮助这位博主，编写一个程序来回答他的问题。

The first line contains an integer $t$ ($1 \le t \le 10\,000$) —the number of test cases.

Each of the following $t$ lines contains a description of the test case. The description consists of two integers $l$ and $r$ ($1 \le l \le r \le 10^6$) — the largest and smallest numbers of the starships in the store.

第一行包含一个整数 $t$（$1 \le t \le 10\,000$）——测试用例的数量。

接下来的 $t$ 行，每行描述一个测试用例。每行包含两个整数 $l$ 和 $r$（$1 \le l \le r \le 10^6$）——商店中飞船编号的最小值和最大值。

Print $t$ lines, one line for each test case, containing the luckiest starship number in the store.

If there are several ways to choose the luckiest number, output any of them.

输出 $t$ 行，每行对应一个测试用例，包含商店中最幸运的星舰编号。

如果存在多种方式选择最幸运的编号，则输出其中任意一个即可。

Let's look at two test examples:

• the luckiness of the number $59$ is $9 - 5 = 4$;
• the luckiness of $60$ equals $6 - 0 = 6$;
• the luckiness of $61$ equals $6 - 1 = 5$;
• the luckiness of $62$ equals $6 - 2 = 4$;
• the luckiness of $63$ is $6 - 3 = 3$.

Thus, the luckiest number is $60$.

In the fifth test example, the luckiest number is $90$.

我们来看两个测试样例：

• 数字 $59$ 的幸运值为 $9 - 5 = 4$；
• $60$ 的幸运值为 $6 - 0 = 6$；
• $61$ 的幸运值为 $6 - 1 = 5$；
• $62$ 的幸运值为 $6 - 2 = 4$；
• $63$ 的幸运值为 $6 - 3 = 3$。

因此，最幸运的数字是 $60$。

在第五个测试样例中，最幸运的数字是 $90$。