import heapq

def max_element_after_operations(n, k, arr):
    arr = [str(x) for x in arr]
    heapq.heapify(arr)
    for _ in range(k):
        a = heapq.heappop(arr)
        b = heapq.heappop(arr)
        heapq.heappush(arr, a + b)
    return max(arr)

t = int(input())
for _ in range(t):
    n, k = map(int, input().split())
    arr = list(map(int, input().split()))
    print(max_element_after_operations(n, k, arr))