for ass in range(int(input())):
    n,k,m=map(int,input().split())
    list1=list(map(int,input().split()))
    list1.sort()

    total,i=0,0
    for mm in range(k):
        total+=list1[mm]
    if total-n>0:
        print(total-n)
    else:
        print(int(0))