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()))

X=[B[i]-C[i] for i in range(N)]

X.sort(reverse=True)

print(sum(A)+sum(C)+sum(X[:K]))