Count 3 Sister Numbers

Count the three-digit integers in a closed range whose hundreds, tens, and ones digits are pairwise different. The 1..10⁹ constraint appended on the original site conflicts with the three-digit statement, so this site follows the explicit three-digit definition and limits the input range to 100..999.

输入格式

One line with left right (100≤left≤right≤999).

输出格式

Output the number of qualifying three-digit integers.

样例 1

输入：

876 890

输出：

3

样例 2

输入：

100 100

输出：

0

样例 3

输入：

102 102

输出：

1

样例说明

Example 1: only 876, 879, and 890 have three distinct digits, so the output is 3.

Example 2: the two 0s in 100 repeat, so the output is 0.

Example 3: the three digits of 102 are all different, so the output is 1.