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

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.