eolymp
Problems

Numbers

Numbers

There was nothing to do, it was in the evening ... Since Timur has a big team and a lot of paper, the work was found.

Take the number a. Take the number b. And write down all the numbers from a to b. Calculate the sum of all written digits.

Input

Two positive integers a and b (ab). The numbers do not exceed 1012.

Output

Print the sum of all written digits.

Time limit 1 second
Memory limit 128 MiB
Input example #1
1 10
Output example #1
46