**Time limit:**1.00 s**Memory limit:**512 MB

Your task is to count the number of integers between a and b where no two adjacent digits are the same.

# Input

The only input line has two integers a and b.

# Output

Print one integer: the answer to the problem.

# Constraints

- 0 \le a \le b \le 10^{18}

# Example

Input:

123 321

Output:

171