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 color). By the way, the artist did not use the tool of previous problem to create the painting.
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
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
For each test case, print the number of chess boards 8 × 8 embedded within the given painting.