n,k=map(int,input().split())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
C=list(map(int,input().split()))

ans=sum(A)
yummy_diff=[]
for i in range(n):
    yummy_diff.append((B[i]-C[i],i))
    
yummy_diff.sort(reverse=True)

for yd,idx in yummy_diff[:k]:
    ans+=B[idx]

for yd,idx in yummy_diff[k:]:
    ans+=C[idx]
    
print(ans)