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.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
import java.lang.*;

public class C {
	static long mod = 1000000007;

	public static void main(String[] args) throws Exception {
		InputReader in = new InputReader(System.in);
		PrintWriter pw = new PrintWriter(System.out);

		//int t=in.readInt();
		//while(t-->0)
		//{

		int n=in.readInt();
		int k=in.readInt();
		//long n=in.readLong();
		Pair p[]=new Pair[n];
		int a[]=new int[n];
		for(int i=0;i<n;i++)
		{
			a[i]=in.readInt();
		}
		int b[]=new int[n];
		for(int i=0;i<n;i++)
		{
			b[i]=in.readInt();
			p[i]=new Pair(a[i]-b[i],i);
		}
		Arrays.sort(p);
		int s=0;
		for(int i=0;i<k;i++)
		{
			int d=p[i].a;
			int pos=p[i].b;
			s+=a[pos];
		}
		for(int i=k;i<n;i++)
		{
			int d=p[i].a;
			int pos=p[i].b;
			if(d<=0)
				s+=a[pos];
			else
				s+=b[pos];
		}
		//String a=in.readString();

		pw.println(s);	     	

		//}

		pw.close();
	}

	public static long gcd(long x, long y) {
		if (x % y == 0)
			return y;
		else
			return gcd(y, x % y);
	}

	public static int gcd(int x, int y) {
		if (x % y == 0)
			return y;
		else
			return gcd(y, x % y);
	}

	public static int abs(int a, int b) {
		return (int) Math.abs(a - b);
	}

	public static long abs(long a, long b) {
		return (long) Math.abs(a - b);
	}

	public static int max(int a, int b) {
		if (a > b)
			return a;
		else
			return b;
	}

	public static int min(int a, int b) {
		if (a > b)
			return b;
		else
			return a;
	}

	public static long max(long a, long b) {
		if (a > b)
			return a;
		else
			return b;
	}

	public static long min(long a, long b) {
		if (a > b)
			return b;
		else
			return a;
	}

	public static long pow(long n, long p, long m) {
		long result = 1;
		if (p == 0)
			return 1;
		if (p == 1)
			return n;
		while (p != 0) {
			if (p % 2 == 1)
				result *= n;
			if (result >= m)
				result %= m;
			p >>= 1;
			n *= n;
			if (n >= m)
				n %= m;
		}
		return result;
	}

	public static long pow(long n, long p) {
		long result = 1;
		if (p == 0)
			return 1;
		if (p == 1)
			return n;
		while (p != 0) {
			if (p % 2 == 1)
				result *= n;
			p >>= 1;
			n *= n;
		}
		return result;

	}

	static class Pair implements Comparable<Pair> {
		int a, b;

		Pair(int a, int b) {
			this.a = a;
			this.b = b;
		}

		public int compareTo(Pair o) {
			// TODO Auto-generated method stub
			if (this.a != o.a)
				return Integer.compare(this.a, o.a);
			else
				return Integer.compare(this.b, o.b);
			//return 0;
		}

		public boolean equals(Object o) {
			if (o instanceof Pair) {
				Pair p = (Pair) o;
				return p.a == a && p.b == b;
			}
			return false;
		}

		public int hashCode() {
			return new Integer(a).hashCode() * 31 + new Integer(b).hashCode();
		}

		public String toString() {
			return a + " " + b;
		}
	}

	static long sort(int a[]) {
		int n = a.length;
		int b[] = new int[n];
		return mergeSort(a, b, 0, n - 1);
	}

	static long mergeSort(int a[], int b[], long left, long right) {
		long c = 0;
		if (left < right) {
			long mid = left + (right - left) / 2;
			c = mergeSort(a, b, left, mid);
			c += mergeSort(a, b, mid + 1, right);
			c += merge(a, b, left, mid + 1, right);
		}
		return c;
	}

	static long merge(int a[], int b[], long left, long mid, long right) {
		long c = 0;
		int i = (int) left;
		int j = (int) mid;
		int k = (int) left;
		while (i <= (int) mid - 1 && j <= (int) right) {
			if (a[i] <= a[j]) {
				b[k++] = a[i++];
			} else {
				b[k++] = a[j++];
				c += mid - i;
			}
		}
		while (i <= (int) mid - 1)
			b[k++] = a[i++];
		while (j <= (int) right)
			b[k++] = a[j++];
		for (i = (int) left; i <= (int) right; i++)
			a[i] = b[i];
		return c;
	}

	public static int[] radixSort(int[] f) {
		int[] to = new int[f.length];
		{
			int[] b = new int[65537];
			for (int i = 0; i < f.length; i++)
				b[1 + (f[i] & 0xffff)]++;
			for (int i = 1; i <= 65536; i++)
				b[i] += b[i - 1];
			for (int i = 0; i < f.length; i++)
				to[b[f[i] & 0xffff]++] = f[i];
			int[] d = f;
			f = to;
			to = d;
		}
		{
			int[] b = new int[65537];
			for (int i = 0; i < f.length; i++)
				b[1 + (f[i] >>> 16)]++;
			for (int i = 1; i <= 65536; i++)
				b[i] += b[i - 1];
			for (int i = 0; i < f.length; i++)
				to[b[f[i] >>> 16]++] = f[i];
			int[] d = f;
			f = to;
			to = d;
		}
		return f;
	}

	static class InputReader {
		private InputStream stream;
		private byte[] buf = new byte[1024];
		private int curChar;
		private int numChars;
		private SpaceCharFilter filter;

		public InputReader(InputStream stream) {
			this.stream = stream;
		}

		public int read() {
			if (numChars == -1)
				throw new InputMismatchException();
			if (curChar >= numChars) {
				curChar = 0;
				try {
					numChars = stream.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (numChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}

		public int readInt() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		public String readString() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}

		public String readLine() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isEndOfLine(c));
			return res.toString();
		}

		public double readDouble() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			double res = 0;
			while (!isSpaceChar(c) && c != '.') {
				if (c == 'e' || c == 'E')
					return res * Math.pow(10, readInt());
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			}
			if (c == '.') {
				c = read();
				double m = 1;
				while (!isSpaceChar(c)) {
					if (c == 'e' || c == 'E')
						return res * Math.pow(10, readInt());
					if (c < '0' || c > '9')
						throw new InputMismatchException();
					m /= 10;
					res += (c - '0') * m;
					c = read();
				}
			}
			return res * sgn;
		}

		public long readLong() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				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 res * sgn;
		}

		public boolean isSpaceChar(int c) {
			if (filter != null)
				return filter.isSpaceChar(c);
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

		public String next() {
			return readString();
		}

		public interface SpaceCharFilter {
			public boolean isSpaceChar(int ch);
		}

		public boolean isEndOfLine(int c) {
			return c == '\n' || c == '\r' || c == -1;
		}
	}

	//BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
	//StringBuilder sb=new StringBuilder("");
	//InputReader in = new InputReader(System.in);
	//PrintWriter pw=new PrintWriter(System.out);
	//String line=br.readLine().trim();

	//int t=Integer.parseInt(br.readLine());
	//	while(t-->0)
	//{
	//int n=Integer.parseInt(br.readLine());
	//long n=Long.parseLong(br.readLine());
	//String l[]=br.readLine().split(" ");
	//int m=Integer.parseInt(l[0]);
	//int k=Integer.parseInt(l[1]);
	//String l[]=br.readLine().split(" ");
	//l=br.readLine().split(" ");
	/*int a[]=new int[n];
	for(int i=0;i<n;i++)
	{
		a[i]=Integer.parseInt(l[i]);
	}*/
	//System.out.println(" ");	     	

	//}

}
