P12146 【MX-X11-T0】Candy Cookie Chocolate

「CANDY CANDY CANDY COOKIE」 「CANDY CANDY CHOCOLA...」 「"CANDYCHOCANDYCHOCODY..."」 「CHOCOLATE」

You have $a$ candies and $b$ cookies. In each operation, you can perform one of the following two actions: - Choose **either** two candies **or** two cookies and delete them, costing $x$. (You must ensure there are at least two candies or two cookies to perform this operation.) - Choose **one candy and one cookie** and delete them, costing $y$. (You must ensure there is at least one candy and one cookie to perform this operation.) Find the minimum total cost to delete all candies **or** all cookies (or both).

**Multiple test cases.** The first line of input contains an integer $T$ representing the number of test cases. For each test case: Input one line containing four positive integers $a$, $b$, $x$, $y$.

For each test case, output one integer representing the minimum cost.

## Explanation #1 **Sample 1 Explanation:** - For the first test case, use the second operation 4 times to delete all candies and cookies, costing $1 \times 4 = 4$. - For the second test case, use the first operation twice on cookies, then use the second operation once to delete all cookies, costing $5 \times 2 + 3 \times 1 = 13$. ## Constraints For all test cases: $1 \le T \le 10$, $1 \le a, b, x, y \le 10^5$. Translated by DeepSeek R1