tcase=int(raw_input())
for case in range(tcase):
    a,b,c=map(int,raw_input().strip().split())
    fishprice=map(int,raw_input().strip().split())
    fishprice.sort()
    sumprice=0
    for i in range(b):
        sumprice+=fishprice[i]
    if a>=sumprice:
        print 0
    else:
        print sumprice-a