void main()
{
	int bysum(int z);
	int k;
	scanf("%d",&k);
	int *m,*n;
	m=(int*)malloc(k*sizeof(int));
	for(n=m;n<m+k;n++)
		printf("%d\n",bysum(*n));
}
int bysum(int z)
{
	int m,n,*a,*b,sum=0;
	scanf("%d%d",&m,&n);
    a=(int*)malloc(m*n*sizeof(int));
    for(b=a;b<a+m*n;b++)
		scanf("%d",b);
    for(b=a;b<a+n;b++)
		sum=sum+*b;
    for(b=a+(m-1)*n;b<a+m*n;b++)
		sum=sum+*b;
    for(b=a+n;b<a+(m-2)*n+1;b=b+n)
        sum=sum+*b;
	for(b=a+n*2-1;b<a+(m-2)*n+n;b=b+n)
	    sum=sum+*b;
	return(sum);
}