T = int(input())

globalcnt = 0
ansval = 0
seglen = 0
iptstr = ""

lst = []
def dfs(remain):
    global ansval
    global globalcnt
    global seglen
    global iptstr

    if(remain == 0):
        cnt = 0
        for i in lst:
            cnt += i
        if(cnt == globalcnt):
            sums = 0
            st = 0
            for i in lst:
                #print(iptstr[st:st+seglen+i])
                sums += int(iptstr[st:st+seglen+i])
                st += seglen+i
            ansval = min(ansval, sums)
        return;
    
    lst.append(1)
    dfs(remain-1)
    lst.pop()

    lst.append(0)
    dfs(remain-1)
    lst.pop()
    return;

while T != 0:
    T -= 1
    iptstr, k = input().split(' ')
    iptstr = input().split()[0]
    
    k = int(k)
    strlen = len(iptstr)
    seglen = strlen // (k+1)
    #print(strlen, k+1, seglen)

    globalcnt = strlen - (seglen * (k+1))
    ansval = int(iptstr)
    dfs(k+1)
    print(ansval)