int main()
{
	int n,hang,lie,h,*p,i,j,a[10000],place;
	int sum=0;
	scanf("%d",&n);
	for (i=1;i<=n;i++)
	{
		sum=0;
		scanf("%d%d\n",&hang,&lie);
		p=a;
		for (j=1;j<=hang;j++)
		{
			for (h=1;h<=lie;h++)
			{
				scanf("%d",&*(p++));
			}
		
		}
		for (place=0;place<=lie-1;place++)
		{
			p=a+place;
			sum+=*p;
		}
		for (place=2*lie-1;place<hang*lie-1;place+=lie)
		{
			p=a+place;
			sum+=*p;
		}
		for (place=hang*lie-1;place>hang*lie-lie;place--)
		{
			p=a+place;
			sum+=*p;
		}
		for (place=lie;place<=hang*lie-lie;place+=lie)
		{
			p=a+place;
			sum+=*p;
		}
		
		printf("%d\n",sum);
	}
}