n, k =map(int,input().split())
a = list(map(int,input().split()))
b = list(map(int,input().split()))
c = list(map(int,input().split()))
d = [(a[i],b[i]-c[i],i) for i in range(n)]
d.sort(key=lambda x:-x[1])
ans = 0
for i in range(k):
	ans += a[d[i][2]] + b[d[i][2]]
for i in range(k,n):
	ans += a[d[i][2]] + c[d[i][2]]
print(ans)