t=int(raw_input())
for case in range(t): 
	n,k,m = map(int, raw_input().strip().split())
	jg = map(int, raw_input().split())

	jg.sort()

	sum = 0
	for i in range(k):
		sum += jg[i]
	if (sum - n) > 0:
		print sum - n
	else:
		print 0