#-*-coding:utf-8-*-
T=int(raw_input())
for i in range(T):
    n,k,m=map(int,raw_input().strip().split())
    a=map(int,raw_input().strip().split())
    a.sort()
    s=0
    for x in range(k):
        s=s+a[x]
    if s-n>0:
      print s-n
    else:
      print "0"