t=int(raw_input())
while t>0:
	n,k,m=map(int,raw_input().strip().split())
	jk=map(int,raw_input().strip().split())
	jk.sort()
	s=0
	for i in range(k):
		s+=jk[i]
	if s>n:
		print (s-n)
	else:
		print 0
	t-=1