ncase = int(raw_input())
for t in range(ncase):
	ss=0
	n,m,k = map(int,raw_input().strip().split())
	s=map(int,raw_input().strip().split())
	s.sort()
	for j in range(m):
		ss=ss+s[j]
	cc=ss-n
	if cc>0:
		print cc
	else:
		print 0