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