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[i] - c[i] for i in range(n)]
bc.sort(reverse=True)
bca = bc[:k]
ans = sum(a) + sum(c)
print(ans + sum(bca))