#!usr/bin/python
#coding=utf-8
ncase=int(raw_input())
for i in range(ncase):
	sum=0
	n,k,m=map(int,raw_input().strip().split())
	price=map(int,raw_input().strip().split())
	price.sort()
	for j in range(k):
		sum=sum+price[j]
	if n>=sum:
		print 0
	else:
		print sum-n