Black and white painting

Problem Description
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). By the way, the artist did not use the tool of problem A 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
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
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

#include

#include

using namespace std;

int main()

{

int n,m,i;

while(scanf("%d%d%d",&n,&m,&i))

{

    if(n == 0 && m == 0 && i == 0)

        break;

    n = n-7;

    m = m-7;

    if((n*m)%2 == 0)

    {

        cout << (n*m)/2 <<endl;

    }

    else

    {

        if(i == 1)

        {

            cout << (n*m)/2 +1 <<endl;

        }

        if(i == 0)

        {

            cout << (n*m)/2 <<endl;

        }

    }

}

return 0;

}