In Berland each high school student is characterized by academic performance — integer value between 1 and 5.

In high school 0xFF there are two groups of pupils: the group A and the group B. Each group consists of exactly n students. An academic performance of each student is known — integer value between 1 and 5.

The school director wants to redistribute students between groups so that each of the two groups has the same number of students whose academic performance is equal to 1, the same number of students whose academic performance is 2 and so on. In other words, the purpose of the school director is to change the composition of groups, so that for each value of academic performance the numbers of students in both groups are equal.

To achieve this, there is a plan to produce a series of exchanges of students between groups. During the single exchange the director selects one student from the class A and one student of class B. After that, they both change their groups.

Print the least number of exchanges, in order to achieve the desired equal numbers of students for each academic performance.

Input

The first line of the input contains integer number n (1 ≤ n ≤ 100) — number of students in both groups.

The second line contains sequence of integer numbers a1, a2, ..., an (1 ≤ ai ≤ 5), where ai is academic performance of the i-th student of the group A.

The third line contains sequence of integer numbers b1, b2, ..., bn (1 ≤ bi ≤ 5), where bi is academic performance of the i-th student of the group B.

Output

Print the required minimum number of exchanges or -1, if the desired distribution of students can not be obtained.

Examples

Input

4
5 4 4 4
5 5 4 5


Output

1


Input

6
1 1 1 1 1 1
5 5 5 5 5 5


Output

3


Input

1
5
3


Output

-1


Input

9
3 2 5 5 2 3 3 3 2
4 1 4 1 1 2 4 4 1


Output

4
import java.io.*;
import java.util.*;
@SuppressWarnings("unused")
public class Main { //Название класса здесь
	private static boolean IOTypeIsFile = false; //Вид ввода/вывода. true-через файл. false-через консоль.
	private static String FileInput = ""; //Название файла ввода
	private static String FileOutput = "";//Название файла вывода
	private static Scanner in;
	private static PrintStream out, err;

	private static String ts(Object a) {
		return String.valueOf(a);
	}

	private static int ti(String a) {
		return Integer.valueOf(a);
	}

	private static double td(String a) {
		return Double.valueOf(a);
	}

	private static int[] arrayI(int n) {
		int[] ans = new int[n];
		for (int i = 0; i < n; ++i) {
			ans[i] = in.nextInt();
		}
		return ans;
	}

	private static String[] arrayS(int n) {
		String[] ans = new String[n];
		for (int i = 0; i < n; ++i) {
			ans[i] = in.next();
		}
		return ans;
	}

	private static double[] arrayD(int n) {
		double[] ans = new double[n];
		for (int i = 0; i < n; ++i) {
			ans[i] = in.nextDouble();
		}
		return ans;
	}

	private static void SomeVeryLargeUndUselessFunctionName() {
		if (!IOTypeIsFile) {
			err.print(FileInput + FileOutput);
		}
	}

	public static void main(String[] args) {
		err = new PrintStream(System.err);
		if (IOTypeIsFile) {
			File f = new File(FileInput);
			try {
				in = new Scanner(f);
				out = new PrintStream(FileOutput);
			} catch (FileNotFoundException var3) {
				System.err.println("404");
			}
		} else {
			in = new Scanner(System.in);
			out = new PrintStream(System.out);
		}
		run();
		in.close();
		out.close();
	}
	//Код пишут отсюда
	private static void run() {
		int n=in.nextInt();
		int[]a=new int[5],b=new int[5];
		for (int i=0;i<n;i++) {
			int d=in.nextInt();
			switch (d) {
				case 1:a[0]++;break;
				case 2:a[1]++;break;
				case 3:a[2]++;break;
				case 4:a[3]++;break;
				case 5:a[4]++;break;
			}
		}
		for (int i=0;i<n;i++) {
			int d=in.nextInt();
			switch (d) {
				case 1:b[0]++;break;
				case 2:b[1]++;break;
				case 3:b[2]++;break;
				case 4:b[3]++;break;
				case 5:b[4]++;break;
			}
		}
		if (((b[0]+a[0])%2==1)||((b[1]+a[1])%2==1)||((b[3]+a[3]%2)==1)||((b[4]+a[4])%2==1)||((b[2]+a[2])%2==1)) {
			out.println(-1);
		} else {
			int ans=0;
			for (int i=0;i<5;i++) {
				if (a[i]<b[i]) {
					for (int j=i+1;a[i]!=b[i];j++) {
						while ((a[j]>b[j])&&(a[i]!=b[i])) {
							b[j]++;
							a[j]--;
							b[i]--;
							a[i]++;
							ans++;
						}
					}
				} else if (a[i]>b[i]) {
					for (int j=i+1;a[i]!=b[i];j++) {
						while ((a[j]<b[j])&&(a[i]!=b[i])) {
							a[j]++;
							b[j]--;
							a[i]--;
							b[i]++;
							ans++;
						}
					}
				}
			}
			out.println(ans);
		}
	}
}