n, k = [int(x) for x in input().split()]
a = [int(x) for x in input().split()]
b = [int(x) for x in input().split()]
c = [int(x) for x in input().split()]

bmc = [b[i] - c[i] for i in range(n)]

print( sum(a) + sum(c) + sum(sorted(bmc)[-k:]) )