ncase = int(raw_input())
for t in range(ncase):
	n,k,m = map(int, raw_input().strip().split());
	a = map(int, raw_input().split());
	a.sort(reverse=False)
	sum = 0
	for i in range(0,k):
		sum += a[i]
	if sum - n >= 0:
		print sum - n
	else:
		print 0