def optimal_game_cost(t, test_cases):
    results = []
    for n, k, a, b in test_cases:
        a.sort()
        b.sort(reverse=True)
        total = 0
        for i in range(n):
            total += abs(a[i] - b[i])
        results.append(total)
    return results
 
def main():
    t = int(input())
    test_cases = []
    for _ in range(t):
        n, k = map(int, input().split())
        a = list(map(int, input().split()))
        b = list(map(int, input().split()))
        test_cases.append((n, k, a, b))
    for res in optimal_game_cost(t, test_cases):
        print(res)
 
main()
 

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5
2 1
1 7
3 5
3 2
1 5 3
6 2 4
5 4
1 16 10 10 16
3 2 2 15 15
4 1
23 1 18 4
19 2 10 3
10 10
4 3 2 100 4 1 2 4 5 5
1 200 4 5 6 1 10 2 3 4