n,k=map(int,input().split())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
c=list(map(int,input().split()))
ans=sum(a)+sum(c)
d=[b[i]-c[i] for i in range(n)]
d.sort()
d.reverse()
e=d[0:k]
ans+=sum(e)
print(ans)