A14280 | Interesting Function

You are given two integers $l$ and $r$ , where $l < r$ . We will add $1$ to $l$ until the result is equal to $r$ . Thus, there will be exactly $r-l$ additions performed. For each such addition, let's look at the number of digits that will be changed after it.

For example:

- if $l=909$ , then adding one will result in $910$ and $2$ digits will be changed;
- if you add one to $l=9$ , the result will be $10$ and $2$ digits will also be changed;
- if you add one to $l=489999$ , the result will be $490000$ and $5$ digits will be changed.

Changed digits always form a suffix of the result written in the decimal system.

Output the total number of changed digits, if you want to get $r$ from $l$ , adding $1$ each time.

The first line contains an integer $t$ ( $1 \le t \le 10^4$ ). Then $t$ test cases follow.

Each test case is characterized by two integers $l$ and $r$ ( $1 \le l < r \le 10^9$ ).

For each test case, calculate the total number of changed digits if you want to get $r$ from $l$ , adding one each time.