Here is the code the 5th period class wrote:

        /*
        //read int and print that many Xs on a line
        Scanner input = new Scanner(System.in);
        int numX = input.nextInt();
        for(int i=0; i < numX; i++) {
            System.out.print("X");
        }
        System.out.println();
        */
        /*
        //alternate:
        for(int i=input.nextInt(); i > 0; i--) {
            System.out.print("X");
        }
        System.out.println();
        */
       
       /*
       //read 2 ints and print rectange of those dimensions
        Scanner input = new Scanner(System.in);
        int numCols = input.nextInt();
        int numRows = input.nextInt();
        
        for(int j=0; j < numRows; j++) {
            for(int i=0; i < numCols; i++) {
                System.out.print("X");
            }
            System.out.println();
        }
        */
       
       //read 2 ints and print hollow rectange of those dimensions
        Scanner input = new Scanner(System.in);
        int numCols = input.nextInt();
        int numRows = input.nextInt();
        
        for(int j=0; j < numRows; j++) {
            for(int i=0; i < numCols; i++) {
                if(i == 0 || i == numCols-1 || j == 0 || j == numRows-1) {
                    System.out.print("X");
                } else {
                    System.out.print(" ");
                }
            }
            System.out.println();
        }