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.text.DecimalFormat;
import java.util.*;
import java.io.*;
import java.math.*;
public class Main {
	public static long mod= (long) (1e9 +7);
	static InputReader s;
	static PrintWriter out;
	public static void main(String args[]) {
		new Thread(null, new Runnable() {
			public void run() {
				try{
					solve();
					out.flush();
					out.close();
				}
				catch(Exception e){
					e.printStackTrace();
				}
			}
		}, "1", 1 << 26).start();
	}
	public static void solve() throws IOException{
		s= new InputReader(System.in);
		OutputStream outputStream= System.out;
		out= new PrintWriter(outputStream);
		int n= s.nextInt();
		int k= s.nextInt();
		int a[]= new int[n];
		int b[]= new int[n];
		for(int i=0;i<n;i++)
			a[i]= s.nextInt();
		for(int i=0;i<n;i++)
			b[i]=s.nextInt();
		int c[]= new int[n];
		Pair p[]= new Pair[n];
		for(int i=0;i<n;i++){
			c[i]= a[i]-b[i];
			p[i]= new Pair(c[i], a[i], b[i]);
		}
		Arrays.sort(p);
		long ans=0;
		int i;
		for(i=0;i<k || (i<n && p[i].a<0);i++){
			ans+= p[i].b;
			//System.out.println(i);
		}
		for(int j=i;j<n;j++){
			ans+= p[j].c;
		}
		out.println(ans);
	}
	
	static long combinations(long n,long r){   // O(r)
		if(r==0 || r==n) return 1;
		r= Math.min(r, n-r);
		long ans=n;  // nC1=n;
		for(int i=1;i<r;i++){
			ans= (ans*(n-i))%mod;
			ans= (ans*modulo(i+1,mod-2,mod))%mod;///(i+1);
		}
		return ans;
	}
	
	static long modulo(long x,long y,long p)	
	{
		 long res = 1;
		 x = x % p;  
		 
	    while (y > 0)
	    {
	        if (y%2==1)
	            res = (res*x) % p;
	 
	        y = y>>1;
	        x = (x*x) % p;  
	    }
	    return res;
	}
	
	static HashSet<Integer> primeFactors(int n)   // O(sqrt(n))
	{
	    // Print the number of 2s that divide n
		HashSet<Integer> arr= new HashSet<>();
	    while (n%2 == 0)
	    {
	        arr.add(2);
	        n = n/2;
	    }
	 
	    // n must be odd at this point.  So we can skip one element (Note i = i +2)
	    for (int i = 3; i <= Math.sqrt(n); i = i+2)
	    {
	        // While i divides n, print i and divide n
	        while (n%i == 0)
	        {
	            arr.add(i);
	            n = n/i;
	        }
	    }
	    // This condition is to handle the case when n is a prime number
	    // greater than 2
	    if (n > 2)
	        arr.add(n);
	    
	    return arr;
	}
 
	public static long expo(long a, long b){
		if (b==0)
	        return 1;
	    if (b==1)
	        return a;
	    if (b==2)
	        return a*a;
 
	    if (b%2==0){
	            return expo(expo(a,(b/2)),2);
	    }
	    else{
	        return a*expo(expo(a,(b-1)/2),2);
	    }
	}
	static class Pair implements Comparable<Pair>
	{
		int a;
		int b;
		int c;
		Pair(int aa, int bb,int cc)
		{
			a= aa;
			b= bb;
			c=cc;
		}
		
		public int compareTo(Pair o) 
		{
			int ans = Integer.compare(this.a,o.a);
			return ans;
//			return ans==0 ? -Integer.compare(this.b, o.b):ans;
//			if(Long.compare(this.x, o.x)!=0)
//				return -Long.compare(this.x, o.x);
//			else
//				return Long.compare(this.y, o.y);
//			return Integer.compare(this.x, o.x);
	//		return Long.compare(this.x, o.x);
		}
		
//		public int hashCode() {
//			int hu = (int) (x ^ (x >>> 32));
//			int hv = (int) (y ^ (y >>> 32));
//			return 31 * hu + hv;
//		}
// 
//		public boolean equals(Object o) {
//			Pair other = (Pair) o;
//			return x == other.x && y == other.y;
//		}
//		
//		public String toString() {
//			return "[x=" + x + ", y=" + y + "]";
//		}
//		
	}
	
	public static int[] sieve(int N){    // O(n*log(logn))
		int arr[]= new int[N+1];
		for(int i=2;i<=Math.sqrt(N);i++){
			if(arr[i]==0){
				for(int j= i*i;j<= N;j= j+i){
					arr[j]=1;
				}
			}
		}
		return arr;
		// All the i for which arr[i]==0 are prime numbers.
	}
	static int gcd(int a,int b){       // O(logn)
		if(b==0) return a;
		return gcd(b,a%b);
	}
	
	public static void debug(Object... o) {
		System.out.println(Arrays.deepToString(o));
	}
	
	static void catalan_numbers(int n) {
		long catalan[]= new long[n+1];
	    catalan[1] = 1;
	    for (int i = 2; i <= n; i++) {
	        for (int j = 1; j <= i - 1; j++) {
	            catalan[i] = catalan[i] + ((catalan[j]) * catalan[i - j]);
	        }
	    }
	}
	
	static final class InputReader{
        private final InputStream stream;
        private final byte[] buf=new byte[1024];
        private int curChar;
        private int Chars;
        public InputReader(InputStream stream){this.stream=stream;}
		private int read()throws IOException{
            if(curChar>=Chars){
                curChar=0;
                Chars=stream.read(buf);
                if(Chars<=0)
                    return -1;
            }
            return buf[curChar++];
        }
        public final int nextInt()throws IOException{return (int)nextLong();}
        public final long nextLong()throws IOException{
            int c=read();
            while(isSpaceChar(c)){
                c=read();
                if(c==-1) throw new IOException();
            }
            boolean negative=false;
            if(c=='-'){
                negative=true;
                c=read();
            }
            long res=0;
            do{
                if(c<'0'||c>'9')throw new InputMismatchException();
                res*=10;
                res+=(c-'0');
                c=read();
            }while(!isSpaceChar(c));
            return negative?(-res):(res);
        }
        public final int[] nextIntBrray(int size)throws IOException{
            int[] arr=new int[size];
            for(int i=0;i<size;i++)arr[i]=nextInt();
            return arr;
        }
        public final String next()throws IOException{
            int c=read();
            while(isSpaceChar(c))c=read();
            StringBuilder res=new StringBuilder();
            do{
                res.append((char)c);
                c=read();
            }while(!isSpaceChar(c));
            return res.toString();
        }
        public final String nextLine()throws IOException{
            int c=read();
            while(isSpaceChar(c))c=read();
            StringBuilder res=new StringBuilder();
            do{
                res.append((char)c);
                c=read();
            }while(c!='\n'&&c!=-1);
            return res.toString();
        }
        private boolean isSpaceChar(int c){
            return c==' '||c=='\n'||c=='\r'||c=='\t'||c==-1;
        }
    }
}