Unique Digits in Range

Given the closed interval [a,b], count the integers whose decimal representation has no repeated digit. The number 0 also counts as a valid integer.

The original rules are clear; this site adds the handling of zero, the upper bound and the standard input/output.

输入格式

One line with two integers a b (0≤a≤b≤10^18).

输出格式

Output the number of integers in the interval whose decimal digits are all distinct.

样例 1

输入：

5 11

输出：

6

样例 2

输入：

0 0

输出：

1

样例 3

输入：

98 102

输出：

2