Count Numbers Without Repeating Digits

Count the non-negative integers in a closed range whose decimal digits are all different. 0 is written as the single digit 0 and counts as valid. The original statement is truncated; the rule is restored from the title and the original explanation that 10..13 includes 10, 12, and 13. The non-negative domain and the representation of 0 are an explicit protocol of this site.

输入格式

One line with start end. The original has no numeric bounds; this site uses 0≤start≤end≤10^18.

输出格式

Output a single integer answer.

样例 1

输入：

10 13

输出：

3

样例 2

输入：

0 11

输出：

11

样例 3

输入：

98 102

输出：

2

样例说明

The outputs of the three public examples are, in order: 3; 11; 2. These answers have been checked by independent enumeration or direct simulation.