t=int(input())
for tt in range(t):
  n,k,m=list(map(int,input().split()))
  a=list(map(int,input().split()))
  a.sort()
  s=0
  for i in range(k):
    s+=a[i]
  if s>n:
          print(s-n)
  else:
          print(0)