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

Sample Input
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8 8 0
8 8 1
9 9 1
40000 39999 0
0 0 0

Sample Output
-------------
0
1
2
799700028