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 = []
for i, (b, c) in enumerate(zip(B, C)):
  D.append((b-c, i))
D.sort()

ans = 0
cnt = 0
while D:
  _, i = D.pop()
  ans += A[i]
  ans += B[i] if cnt < K else C[i]
  cnt += 1

print(ans)