for i in range(int(input())):

    n,k,m=map(int,input().split())

    a=list(map(int,input().split()))
    

    a.sort()
    
    
    
    s=0
    for j in range(k):
        s=s+a[j]

    if s>n:
        print(s-n)
    else:
        print(0)