extern void object::Solution( )
{
    errmode(0);
    int found [4][4];
    point pos;
    for ( int x=0 ; x<4 ; x=x+1 )
    {
        for ( int y=0 ; y<4 ; y=y+1 )
	{
             // go to a platform
            pos.x = 10*x;
            pos.y = 10*y;
            goto(pos);
            // try to pick up an object
            grab();
            if ( load == null ) 
            {
                found[x][y] = 0;
            }
            else
            {
                // memorize item found
                found[x][y] = load.category;
                // put it down elsewhere
                move(-2);
                drop(Behind);
            }
	}
    }

    // put objects back
    for ( int x=0 ; x<4 ; x=x+1 )
    {
        for ( int y=0 ; y<4 ; y=y+1 )
        {
            if ( found[y][x] == 0 ) continue;
             // go fetch object
            object item = radar(found[x][y]);
             goto(item.position); grab();
            // put it on a platform
            // x and y are inverted
            pos.x = 10*y;
            pos.y = 10*x;
            goto(pos);
            drop();
	}
    }
}