int main()
{
	int n;
	scanf("%d",&n);
	int i = 1;
	for(i;i<=n;i++)
	{
		int p,q;
		scanf("%d %d",&p,&q);
		int a[10000];
for(int j = 0;j<p*q;j++)
scanf("%d",&a[j]);
		int sum = 0;
		int m=0;
		while(m<q)
		{
			sum = sum + a[m];
			m++;
		}
		m = (p - 1) * q ;
		while(m<p*q)
		{
			sum = sum + a[m];
			m++;
		}
		m = 1;
		while(m<p-1)
		{
			sum = sum + a[q*m];
			m++;
		}
		m = 2;
		while(m<p)
		{
			sum = sum +a[q*m-1];
			m++;
		}
		printf("%d\n",sum);
	}
	return 0;
}