Problem Description

Windy defines a number called "windy number." A positive integer without leading zeros and with the absolute difference between any two consecutive digits being at least $2$ is called a windy number. Windy wants to know how many windy numbers exist between $a$ and $b$, inclusive.

Input Format

The input consists of a single line with two integers, representing $a$ and $b$ respectively.

Output Format

Output a single integer representing the answer.

Sample Input and Output

Sample Input #1

1 10

Sample Output #1

9

Sample Input #2

25 50

Sample Output #2

20

Notes

Data Size and Constraints

For all test cases, it is guaranteed that $1 \leq a \leq b \leq 2 \times 10^9$.

见题面 Input 部分

见题面 Output 部分