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 in range(N):
    D.append((A[i], B[i], C[i], B[i]-C[i]))
D.sort(key=lambda x:x[3], reverse=True)

ans = 0
for i in range(K):
    ans += D[i][0]+D[i][1]
for i in range(K, N):
    ans += D[i][0]+D[i][2]

print(ans)