#!/usr/bin/python
t=int(raw_input())
for i in range(t):
    n,k,m=map(int,raw_input().strip().split())
    if (m<k) :
        break
    jg=map(int,raw_input().strip().split())
    jg.sort()
    pay=0
    for h in range(k):
        pay+=jg[h]
    if n<pay:
        print pay-n
    else:
        print 0