Igor found out discounts in a shop and decided to buy n items. Discounts at the store will last for a week and Igor knows about each item that its price now is ai, and after a week of discounts its price will be bi.

Not all of sellers are honest, so now some products could be more expensive than after a week of discounts.

Igor decided that buy at least k of items now, but wait with the rest of the week in order to save money as much as possible. Your task is to determine the minimum money that Igor can spend to buy all n items.

Input

In the first line there are two positive integer numbers n and k (1 ≤ n ≤ 2·105, 0 ≤ k ≤ n) — total number of items to buy and minimal number of items Igor wants to by right now.

The second line contains sequence of integers a1, a2, ..., an (1 ≤ ai ≤ 104) — prices of items during discounts (i.e. right now).

The third line contains sequence of integers b1, b2, ..., bn (1 ≤ bi ≤ 104) — prices of items after discounts (i.e. after a week).

Output

Print the minimal amount of money Igor will spend to buy all n items. Remember, he should buy at least k items right now.

Examples

Input

3 1
5 4 6
3 1 5


Output

10


Input

5 3
3 4 7 10 3
4 5 5 12 5


Output

25

Note

In the first example Igor should buy item 3 paying 6. But items 1 and 2 he should buy after a week. He will pay 3 and 1 for them. So in total he will pay 6 + 3 + 1 = 10.

In the second example Igor should buy right now items 1, 2, 4 and 5, paying for them 3, 4, 10 and 3, respectively. Item 3 he should buy after a week of discounts, he will pay 5 for it. In total he will spend 3 + 4 + 10 + 3 + 5 = 25.

import java.io.*;
import java.util.*;
public class test {
    int max = 0;
    long max1 = 0;
    boolean visited[];
    int color[];
    boolean bi=true;
    ArrayList<Integer> b=new ArrayList<>();
    ArrayList<Integer> c=new ArrayList<>();
    PrintStream out = System.out;
    int signx[] = {1,-1,0 ,0, 1, -1,-1,1};
    int signy[]=  {0,0,1,-1,  1,-1,1,-1};
    ArrayList<Integer> queue = new ArrayList<>();
    public class CustomComparator implements Comparator<Map.Entry<Integer,Integer>> {
        public int compare(Map.Entry o1, Map.Entry o2) {
            int t= (int) o1.getKey();
            int q=(int)o2.getKey();
            return t-q;
        }
    }
    public static void main(String args[]) throws IOException {
        test obj = new test();
        obj.start();
    }

    void start() throws IOException {
        Reader sc = new Reader();
        //  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        //Scanner sc = new Scanner(System.in);
        int n=sc.nextInt();
        int m=sc.nextInt();
        int a[]=intArray(n,sc);
        int b[]=intArray(n,sc);
        ArrayList<Pair<Integer,Integer>> list=new ArrayList<>();
        ArrayList<Pair<Integer,Integer>> list1=new ArrayList<>();
        for(int i=0;i<n;i++)
        {
            list.add(new Pair<>(a[i]-b[i],a[i]));
            list1.add(new Pair<>(a[i]-b[i],b[i]));
        }
        Collections.sort(list,(Pair<Integer, Integer> o1, Pair<Integer, Integer> o2) -> o1.a.compareTo(o2.a));
        Collections.sort(list1,(Pair<Integer, Integer> o1, Pair<Integer, Integer> o2) -> o1.a.compareTo(o2.a));
        int sum=0;
        for(int i=0;i<n;i++)
        {
            if(i<m||list.get(i).getKey()<0) {
              //  out.println(list.get(i).getValue());
                sum += list.get(i).getValue();
            }
            else
            {
                sum+=list1.get(i).getValue();
            }

        }
        out.println(sum);
    }


    //<---------------------------------------------------------------------------------------------------------------->//

    //printing 2-d array
    private void println(int[][] a,int n,int m) {
        for(int i=0;i<n;i++)
        {
            for(int j=0;j<m;j++)
                System.out.print(a[i][j]+" ");
            System.out.println();
        }

    }
    void println(ArrayList<Integer> a)
    {
        for (int b:a
                ) {
            System.out.print(b+" ");
        }
    }


    //modified dfs for chessboard, matrix
  /*  void dfs(char a[][],int i,int j,char t,int n,int m)
    {
        //visited[i]=true;
        a[i][j]=t;
        if(t=='B')
            t='W';
        else
            t='B';
        for (int c= 0; c < 4; c++) {

            int temp=i+sign[2*c];
            int temp2=j+sign[2*c+1];
            if(temp>=0&&temp<n&&temp2>=0&&temp2<m) {
                if(a[temp][temp2]=='.'&&a[temp][temp2]!='-')
                    dfs(a,temp,temp2,t,n,m);
            }
        }
    }*/


     //constructing segment tree
    private void constructseg(long[] seg, long[] input, int p, int q, int pos) {
        if(p==q)
        {
            seg[pos]=input[p];
            return;
        }
        int mid=(q+p)/2;
        constructseg(seg,input,p,mid,2*pos+1);
        constructseg(seg,input,mid+1,q,2*pos+2);
        seg[pos]=seg[2*pos+1]+seg[2*pos+2];
    }

     void bipartite(ArrayList<Integer> a[],int i)
     {
         int presentcolor=color[i];
         int nextcolor;
         if(color[i]==0) {
             nextcolor=1;
           b.add(i);
         }
         else
         {
             nextcolor=0;
             c.add(i);
         }
         for(int j=0;j<a[i].size();j++)
         {
             if(color[a[i].get(j)]==presentcolor)
                 bi=false;
             else if(color[a[i].get(j)]==-1)
             {
                 color[a[i].get(j)]=nextcolor;
                 bipartite(a,a[i].get(j));
             }
         }

     }
    //traversing through a arrayList graph
    void dfs(ArrayList<Integer> node[],int i,int max1)
    {
        if(max1==2) {
            c.add(i);
            max1 = 1;
        }
        else
        {
            max1=2;
            b.add(i);
        }
        visited[i]=true;
   /*     if(cat[i]==1) {
            count++;
        }
        else
            count=0;
        if(count>k) {
            return;
        }
        if(node[i].size()==1&&i!=0) {
            max += 1;
        }*/
        for (int j = 0; j < node[i].size(); j++) {
            if(!visited[node[i].get(j)]) {
                max--;
                dfs(node, node[i].get(j),max1);
            }
        }

    }


    //printing arraylist array
    void println(ArrayList<Integer> a[])
    {
          for (ArrayList<Integer> b:a
               ) {
              System.out.println(b.toString());
          }
    }

    //sorting 2 array based on a, Complexity is O(n^2)
    void sort(int a[],int b[],int n)
    {
        for(int i=1;i<n;i++)
        {
            int index=i;
            for(int j=i-1;j>=0;j--)
            {
              //  println(a);
                if(a[index]<a[j])
                {
                    int temp=a[index];
                    int temp2=b[index];
                    a[index]=a[j];
                    b[index]=b[j];
                    a[j]=temp;
                    b[j]=temp2;
                    index=j;

                }
                else
                    break;
            }
        }

    }
     // to create and initialize Integer array
    private int[] intArray(int a, Scanner sc) {
        int temp[]=new int[a];
        for(int i=0;i<a;i++) {
            temp[i]=sc.nextInt();
        }
        return temp;
    }

    private int[] intArray(int a, Reader sc) throws IOException {
        int temp[]=new int[a];
        for(int i=0;i<a;i++) {
            temp[i]=sc.nextInt();
        }
        return temp;
    }// / to create and initialize Long Array
    private long[] longArray(int a, Scanner sc) {
        long temp[]=new long[a];
        for(int i=0;i<a;i++) {
            temp[i]=sc.nextLong();
        }
        return temp;
    }

    // displaying Map contents key--value
    public static void printMap(Map mp) {
        Iterator it = mp.entrySet().iterator();
        while (it.hasNext()) {
            Map.Entry pair = (Map.Entry)it.next();
            System.out.println(pair.getKey() + " = " + pair.getValue());
            it.remove(); // avoids a ConcurrentModificationException
        }
    }


    // Return arrayList of minimum factor of number
    // 24= 2*2*2*3;
    private ArrayList<Integer> minFactor(int a) {
        ArrayList<Integer> obj=new ArrayList<>();
        for(int i=2;i<=a;i++)
        {
            while(a!=0&&a%i==0)
            {
                obj.add(i);
                a/=i;
            }
        }
        return obj;
    }


    // check whether the number is prime or not
    public static boolean isPrimeNumber(int i) {
        int factors = 0;
        int j = 1;

        while(j <= i)
        {
            if(i % j == 0)
            {
                factors++;
            }
            j++;
        }
        return (factors == 2);
    }

    // creating and initializing arrayList
    private void initArrayList(ArrayList<Integer>[] tempa) {
        for(int i=0;i<tempa.length;i++)
            tempa[i]=new ArrayList<>();
    }

    // return factorial contents as ArrayList
    private ArrayList<Integer> factdigit(int i)
    {
        ArrayList<Integer> temp=new ArrayList<>();
        for(int j=i;j>1;j--)
        {
            temp.add(j);
        }
        return temp;
    }

    //printing Integer array
    private  void println(int a[])
    {
        for(int i=0;i<a.length;i++)
            System.out.print(a[i]+" ");
    }
    int factorial(int n){
        if (n == 0)
            return 1;
        else
            return((n %1000000007)* (factorial(n-1)%1000000007));
    }
}





class Reader {
    final private int BUFFER_SIZE = 1 << 16;
    private DataInputStream din;
    private byte[] buffer;
    private int bufferPointer, bytesRead;

    public Reader() {
        din = new DataInputStream(System.in);
        buffer = new byte[BUFFER_SIZE];
        bufferPointer = bytesRead = 0;
    }

    public Reader(String file_name) throws IOException {
        din = new DataInputStream(new FileInputStream(file_name));
        buffer = new byte[BUFFER_SIZE];
        bufferPointer = bytesRead = 0;
    }

    public String readLine() throws IOException {
        byte[] buf = new byte[300]; // line length
        int cnt = 0, c;
        while ((c = read()) != -1) {
            if (c == '\n')
                break;
            buf[cnt++] = (byte) c;
        }
        return new String(buf, 0, cnt);
    }

    public int nextInt() throws IOException {
        int ret = 0;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();
        do {
            ret = ret * 10 + c - '0';
        } while ((c = read()) >= '0' && c <= '9');

        if (neg)
            return -ret;
        return ret;
    }

    public long nextLong() throws IOException {
        long ret = 0;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();
        do {
            ret = ret * 10 + c - '0';
        }
        while ((c = read()) >= '0' && c <= '9');
        if (neg)
            return -ret;
        return ret;
    }

    public double nextDouble() throws IOException {
        double ret = 0, div = 1;
        byte c = read();
        while (c <= ' ')
            c = read();
        boolean neg = (c == '-');
        if (neg)
            c = read();

        do {
            ret = ret * 10 + c - '0';
        }
        while ((c = read()) >= '0' && c <= '9');

        if (c == '.') {
            while ((c = read()) >= '0' && c <= '9') {
                ret += (c - '0') / (div *= 10);
            }
        }

        if (neg)
            return -ret;
        return ret;
    }

    private void fillBuffer() throws IOException {
        bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
        if (bytesRead == -1)
            buffer[0] = -1;
    }

    private byte read() throws IOException {
        if (bufferPointer == bytesRead)
            fillBuffer();
        return buffer[bufferPointer++];
    }

    public void close() throws IOException {
        if (din == null)
            return;
        din.close();
    }
}

//Pair implementation
class Pair<A, C> {
    public final A a;
    public final C c;

    Pair(A a, C c) {
        this.a = a;
        this.c = c;
    }
    A getKey()
    {
        return this.a;
    }
    C getValue()
    {
        return this.c;
    }
    void print()
    {
        System.out.println(this.a+" "+this.c);
    }
}
