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