#P1848D. Vika and Bonuses
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ID: 9883
Type: RemoteJudge
3000ms
256MiB
Tried: 0
Accepted: 0
Difficulty: 8
Uploaded By:
Hydro
Tags> Vika and Bonuses
Description
A new bonus system has been introduced at Vika's favorite cosmetics store, "Golden Pear"!
The system works as follows: suppose a customer has bonuses. Before paying for the purchase, the customer can choose one of two options:
- Get a discount equal to the current number of bonuses, while the bonuses are not deducted.
- Accumulate an additional bonuses, where is the last digit of the number . As a result, the customer's account will have bonuses.
For example, if a customer had bonuses, he can either get a discount of or accumulate an additional bonuses, after which his account will have bonuses.
At the moment, Vika has already accumulated bonuses.
The girl knows that during the remaining time of the bonus system, she will make more purchases at the "Golden Pear" store network.
After familiarizing herself with the rules of the bonus system, Vika became interested in the maximum total discount she can get.
Help the girl answer this question.
Each test consists of multiple test cases. The first line contains a single integer () — the number of test cases. The description of the test cases follows.
The test case consists of a single line containing two integers and (, ) — the current number of bonuses in Vika's account and how many more purchases the girl will make.
For each test case, output a single integer — the maximum total discount that can be obtained through the bonus system.
Input
Each test consists of multiple test cases. The first line contains a single integer () — the number of test cases. The description of the test cases follows.
The test case consists of a single line containing two integers and (, ) — the current number of bonuses in Vika's account and how many more purchases the girl will make.
Output
For each test case, output a single integer — the maximum total discount that can be obtained through the bonus system.
Note
In the first test case, Vika can accumulate bonuses after the first and second purchases, after which she can get a discount of .
In the second test case, Vika can get a discount of three times, and the total discount will be .
In the third example, regardless of Vika's actions, she will always get a total discount of .