#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
using namespace std;
int main(void) 
{
	int x, y, z, p, q, r;
	scanf ("%d", &x);
	for (x; x > 0; --x)
	{
		scanf ("%d%d", &y, &z);
		int a[y];
		for (p = 0; p < y; ++p)
		{
			scanf ("%d", &a[p]);
		}
		sort (a, a + y - 1);
		q = 0;
		for (p = 0; p < z; ++p)
		{
			q = q + a[p];
		}
		r = 0;
		for (p = z; p < y; ++p)
		{
			r = r + a[p];
		}
		printf ("%d\n", abs(q - r));
	}
	return 0;
}

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2
5 2
8 4 5 2 10
8 3
1 1 1 1 1 1 1 1