#include <cstdio>

using namespace std;
const int limitastanga = - 50000;
const int limitadreapta = 50000;
int x;
int sirelemente[44110];

void preparation(int n , int m)
{
    int aux = 1;
    for(int i = 1 ; i <= n ; i++)
        for(int j = 1; j <= m ; j++)
            sirelemente[aux++]=i*j;
}




int main()
{
    int n,m;
    freopen("diamant.in","r",stdin);
    freopen("diamant.out","w",stdout);
    scanf("%d %d %d",&n,&m,&x);
    if(x > limitadreapta || x < limitastanga)
    {
        printf("0\n");
        return 0;
    }
    preparation(n,m);
    return 0;
}