import java.io.*;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int k = sc.nextInt();
        long ans = 0;
        for (int i = 0; i < n; i++) {
            ans += sc.nextInt();
        }
        Bird[] birds = new Bird[n];
        for (int i = 0; i < n; i++) {
            birds[i] = new Bird(sc.nextInt());
        }
        for (int i = 0; i < n; i++) {
            birds[i].source = sc.nextInt();
        }
        Arrays.sort(birds);
        for (int i = 0; i < n; i++) {
            if (i < k) {
                ans += birds[i].salt;
            } else {
                ans += birds[i].source;
            }
        }
        System.out.println(ans);
    }
    
    static class Bird implements Comparable<Bird> {
        int salt;
        int source;
        
        public Bird(int salt) {
            this.salt = salt;
        }
        
        public int diff() {
            return salt - source;
        }
        
        public int compareTo(Bird another) {
            return another.diff() - diff();
        }
    }
}

class Scanner {
    BufferedReader br;
    StringTokenizer st = new StringTokenizer("");

    public Scanner() {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
        } catch (Exception e) {
            
        }
    }
    
    public int nextInt() {
        return Integer.parseInt(next());
    }
    
    public long nextLong() {
        return Long.parseLong(next());
    }
    
    public double nextDouble() {
        return Double.parseDouble(next());
    }
    
    public String next() {
        try {
            while (!st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            return st.nextToken();
        }
    }
    
}