/** Represents an array of integers each in the range -8..7. 
 *  Such integers may be represented in 4 bits (called nybbles). */
public class Nybbles {
    /** An array of size N. */
    public Nybbles (int N) {
        // DON'T CHANGE THIS.
        data = new int[ (N+7) / 8 ];
        this.N = N;
    }

    /** The size of THIS. */
    public int size () { return N; }

    /** Return the Kth integer in THIS array, numbering from 0. 
     *  Assumes 0 <= K < N. */
    public int get (int k) {
        if (k < 0 || k >= N)
            throw new IndexOutOfBoundsException ();
        else 
            return /* REPLACE WITH ANSWER */ 0;
    }

    /** Set the Kth integer in THIS array to VAL.  Assumes 
     *  0 <= K < N and -8 <= VAL < 8. */
    public void set (int k, int val) {
        if (k < 0 || k >= N)
            throw new IndexOutOfBoundsException ();
        else if (val < -8 || val >= 8)
            throw new IllegalArgumentException ();
        else 
            data[ /* REPLACE WITH ANSWER */ 0 ] =
                /* REPLACE WITH ANSWER */ 0;
    }

    // DON'T CHANGE OR ADD TO THESE.
    private int N;
    private int[] data;
}