t=int(input())
while t:
    n,k,m=map(int,input().split())
    a=list(map(int,input().split()))
    a.sort()
    iSum=0
    for i in range(k):
        iSum+=a[i]
    if iSum<=n:
        print(0)
    else:
        print(iSum-n)
    t=t-1