import java.io.*;
import java.util.*;

public class <CLASSNAME>
{
	public static void main(String[] arg)
	{
		Scanner sc = new Scanner(System.in);
		int T = sc.nextInt();
		for(int C=1; C<=T; ++C)
		{
			System.out.printf("Case #%d: ", C);
			(new <CLASSNAME>(sc)).caseMain();
		}
	}

	Scanner sc;
	<CLASSNAME>( Scanner sc ) { this.sc = sc; }

	void caseMain()
	{
		int n = sc.nextInt();
		long[] x = new long[n];
		for(int i=0; i<n; ++i) x[i] = sc.nextInt();
		long[] y = new long[n];
		for(int i=0; i<n; ++i) y[i] = sc.nextInt();

		System.out.println(solve(x, y, n));
	}

	long solve(long[] x, long[] y, int n)
	{
		Arrays.sort(x);
		Arrays.sort(y);
		long s = 0;
		for(int i=0; i<n; ++i)
			s += x[i] * y[n-1-i];
		return s;
	}
}
