T=int(raw_input())
for i in range(T):
	n,k,m=map(int,raw_input().strip().split())
	kind=map(int,raw_input().strip().split())
	kind.sort()
	sum=0
	for j in range(k):
		sum+=kind[j]
	if sum-n<=0:
		print "0"
	else:	
		print sum-n