N,K=map(int,input().split())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
C=list(map(int,input().split()))
BC=[b-c for b,c in zip(B,C)]
BC.sort(reverse=True)
ans=sum(A)+sum(C)+sum(BC[:K])
print(ans)