# Tuenti Challenge 8

## Challenge 1 - Waffle love

Your store, 20 Waffles, is famous for having the most beautiful and delicious waffles in the entire city. You and your staff have put a lot of effort into making sure the shape of your most requested product, the rectangular waffle, is always perfect and that your customers are always happy with them. Sometimes, they even count the number of holes in your waffles. Sometimes they even ask you for help.

Given each waffle’s number of vertical and horizontal lines, how many holes does it have?

### Input

The first line has an integer C, which is the number of cases for the problem. Then C lines follow and each one has two integers N and M, which are the number of vertical and horizontal lines on the waffle.

### Output

For each case, there should be a line starting with "Case #x: " followed by the number of holes in the waffle.

### Limits

• 1 ≤ C ≤ 100
• 2 ≤ N, M ≤ 10000

```3
2 2
3 2
4 3
```

### Sample Output

```Case #1: 1
Case #2: 2
Case #3: 6
```

Here are some diagrams for the cases above to help you understand the problem better.

 1
2x2
 1 2
3x2
 1 2 3 4 5 6
4x3

You can test your program against both the input provided in the test phase and the input provided in the submit phase. A nice output will tell you if your program got the right solution or not. You can try as many times as you want to. Be careful with extra whitespaces, the output should be exactly as described.

Program output: