import sys
input = sys.stdin.readline
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 b, c in zip(B, C):
    D.append((b-c, b, c))
D.sort()
ans = sum(A)
for i in range(N-K):
    _, b, c = D[i]
    ans += c
for i in range(N-K, N):
    _, b, c = D[i]
    ans += b
print(ans)