**Description**

1680. Black and white painting

You are visiting the Centre Pompidou which contains a lot of modern paintings. In particular you notice one painting which consists solely of black and white squares, arranged in rows and columns like in a chess board (no two adjacent squares have the same colour).

Since you are bored, you wonder how many 8 × 8 chess boards are embedded within this painting. The bottom right corner of a chess board must always be white.

**Input Specification**

The input contains several test cases. Each test case consists of one line with three integers n, m and c. (8 ≤ n, m ≤ 40000), where n is the number of rows of the painting, and m is the number of columns of the painting. c is always 0 or 1, where 0 indicates that the bottom right corner of the painting is black, and 1 indicates that this corner is white.

The last test case is followed by a line containing three zeros.

**Output Specification**

For each test case, print the number of chess boards embedded within the given painting.

**Sample Input**

8 8 0

8 8 1

9 9 1

40000 39999 0

0 0 0

**Sample Output**

0

1

2

799700028

**Ancillary Files**

Input file: black.in

Output file: black.out

**Solution** (File: 1680.py)

#### Solution

Runs < 0.001 seconds in Python 2.7.Use this link to get the Project Euler Solution Python 2.7 source.

#### Afterthoughts

- Run from cmd prompt as: python 1680.py < black.in > my_black.out
- and compare my_black.out to black.out. Submit the program to the SPOJ server at the link provided under the description.
- The test cases are qualified to match the input specification.

## Discussion

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