N,K=map(int,input().split())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
C=list(map(int,input().split()))



oisisa=sum(A)


E=[[B[i]-C[i],i]for i in range(N)]

E=sorted(E,reverse=1)


for i in range(K):
    oisisa+=B[E[i][1]]
for i in range(N-K):
    oisisa+=C[E[-i-1][1]]
print(oisisa)