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 = sorted([(B[i] -C[i], i) for i in range(N)], reverse=True)


ans = 0
for i in range(K):
    j, k = BC[i]
    ans += A[k] +B[k]

for j in range(K, N):
    i, k = BC[j]
    ans += A[k] +C[k]

print(ans)