N, K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))

diff = []
for i in range(N):
  diff.append((B[i], C[i], B[i] - C[i]))

diff.sort(key = lambda x: x[-1], reverse = True)

ans = sum(A)
for i in range(N):
  if i < K:
    ans += diff[i][0]
  else:
    ans += diff[i][1]

print(ans)