#P15544. [CCC 2026 S5] On the Fence

[CCC 2026 S5] On the Fence

Description

You recently inherited a beautiful plot of land, which can be viewed as a grid with NN rows and MM columns. Now you want to protect your land from trespassers by building a giant fence on it. You will build this fence by choosing up to KK grid cells and filling each of them with a concrete block; these cells are on the fence. Due to mysterious construction laws, the cell in row RR and column CC must be on the fence. Also, the fence cells must form a single connected component—you should be able to get between any two cells on the fence by moving vertically or horizontally (not diagonally) through fence cells only.

The cells in row 1, column 1, row NN, and column MM are called edge cells. A cell not on the fence is outside the fence if you can get from that cell to an edge cell by moving vertically, horizontally, or diagonally, without going through any fence cells. Otherwise, the cell is inside the fence. The figure below shows some examples of valid and invalid fences.

:::align{center} :::

You want to protect as much of your land as possible. Find the largest number of inside cells you can enclose within your fence.

Input Format

The first line of input contains an integer TT, the number of test cases in the input.

The next TT lines each contain a test case, consisting of five space-separated integers: NN, MM, KK, RR, and CC (1KNM1 \le K \le NM, 1RN1 \le R \le N, 1CM1 \le C \le M).

Output Format

Output TT lines. The tt-th line should contain a single integer, the answer to test case tt.

2
5 6 12 3 4
3 6 18 2 4
4
3

Hint

Explanation of Output for Sample Input

Below are optimal fences for the two test cases, which enclose 4 and 3 inside cells, respectively:

:::align{center} :::

The table on the next page shows how the available 15 marks are distributed.

Marks Awarded Bounds on TT Bounds on N,MN, M Additional Constraints
1 mark T1000T \le 1000 1N,M1091 \le N, M \le 10^9 K=NMK = NM
2 marks T10T \le 10 1N,M61 \le N, M \le 6 None
1N,M401 \le N, M \le 40
1N,M3001 \le N, M \le 300
1N,M20001 \le N, M \le 2000
3 marks 1N,M1061 \le N, M \le 10^6
T1000T \le 1000 1N,M1091 \le N, M \le 10^9