P17260 [ICPC 2017 Urumqi R] The Difference

Alice was always good at math. Her only weak points were multiplication and subtraction. To help her with that, Bob presented her with the following problem. He gave her four positive integers. Alice can change their order optionally. Her task is to find an order, denoted by $A_1, A_2, A_3$ and $A_4$, with the maximum value of $A_1 \times A_2 - A_3 \times A_4$.

The input contains several test cases and the first line provides an integer $t (1 \le t \le 100)$ indicating the number of cases. Each of the following $t$ lines contains four space-separated integers. All integers are positive and not greater than $100$.

For each test case, output a line with a single integer, the maximum value of $A_1 \times A_2 - A_3 \times A_4$.