import java.util.*;
import java.util.concurrent.TimeUnit;
import java.io.*;

public class test31 {
    public static void main(String[] s) throws IOException {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();

        for (int w=0; w<n; w++){
            int k = in.nextInt();
            String a = in.next();
            String b = in.next();

            int c = 0; //the amount of numbers were not changed
            for (int i = 0; i < Math.min(a.length(), b.length()); i++){
                if (a.charAt(i) == b.charAt(i)){
                    c++;
                }else{
                    break;
                }
            }

            int r = (Math.min(a.length(), b.length()) - c) * 2 +
                    (Math.max(a.length(), b.length())-Math.min(a.length(), b.length())); //min amount of changes to get the result

            if (k-r >= 0 && (k-r)%2 == 0){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        }
    }
}