CF833C.Ever-Hungry Krakozyabra

Recently, a wild Krakozyabra appeared at Jelly Castle. It is, truth to be said, always eager to have something for dinner.

Its favorite meal is natural numbers (typically served with honey sauce), or, to be more precise, the zeros in their corresponding decimal representations. As for other digits, Krakozyabra dislikes them; moreover, they often cause it indigestion! So, as a necessary precaution, Krakozyabra prefers to sort the digits of a number in non-descending order before proceeding to feast. Then, the leading zeros of the resulting number are eaten and the remaining part is discarded as an inedible tail.

For example, if Krakozyabra is to have the number 57040 for dinner, its inedible tail would be the number 457.

Slastyona is not really fond of the idea of Krakozyabra living in her castle. Hovewer, her natural hospitality prevents her from leaving her guest without food. Slastyona has a range of natural numbers from L to R, which she is going to feed the guest with. Help her determine how many distinct inedible tails are going to be discarded by Krakozyabra by the end of the dinner.

最近，一只野生的克拉科齐亚布拉（Krakozyabra）出现在果冻城堡（Jelly Castle）。坦白地说，它总是渴望享用一顿晚餐。

它最钟爱的食物是自然数（通常配以蜂蜜酱），更准确地说，是这些自然数在十进制表示中所含的数字 0。至于其他数字，克拉科齐亚布拉非常厌恶；更糟糕的是，它们常常导致它消化不良！因此，为确保安全，克拉科齐亚布拉总是在开餐前将某个数的各位数字按非降序（即升序或相等）排列。接着，它会吃掉所得数的前导零，而将剩余部分作为“不可食用的尾巴”丢弃。

例如，若克拉科齐亚布拉要以数字 57040 为食，则其不可食用的尾巴便是数字 457。

斯拉丝约娜（Slastyona）其实并不太乐意让克拉科齐亚布拉住在她的城堡里。然而，她与生俱来的待客之道又使她无法让这位客人饿着肚子。斯拉丝约娜手头有一段从自然数 L 到 R 的区间，她打算用该区间内的所有数字来喂养这位客人。请你帮她计算：在整场晚宴结束时，克拉科齐亚布拉总共会丢弃多少个互不相同的不可食用的尾巴？

In the first and only string, the numbers L and R are given – the boundaries of the range (1 ≤ L ≤ R ≤ 1018).

在第一行且唯一的一行中，给出两个数 $L$ 和 $R$ —— 表示区间的边界（$1 \leq L \leq R \leq 10^{18}$）。

Output the sole number – the answer for the problem.

输出唯一数字——该问题的答案。

In the first sample case, the inedible tails are the numbers from 1 to 9. Note that 10 and 1 have the same inedible tail – the number 1.

In the second sample case, each number has a unique inedible tail, except for the pair 45, 54. The answer to this sample case is going to be (57 - 40 + 1) - 1 = 17.

在第一个样例中，不可食用的尾数是数字 1 到 9。注意：10 和 1 具有相同的不可食用尾数——数字 1。

在第二个样例中，每个数字都有唯一的不可食用尾数，除了数对 $45,\,54$。本样例的答案为 $(57\,-\,40\,+\,1)\,-\,1\,=\,17$。