public class ccon
    {
        System.Drawing.Graphics zona_des;
        int x0, y0, r0, r;
        public void desenez(Color culoare_contur)
        {
            zona_des.DrawEllipse(new Pen(culoare_contur), x0, y0, r0 + 2, r0 + 2);
        }
        public void sterg(Color culoare_stergere)
        {
            zona_des.FillEllipse(new SolidBrush(culoare_stergere), x0 + 1, y0 + 1, r0 - 1, r0 - 1);
        }

        public void setc(Color culoare_cerc, int r)
        {
            int x = System.Convert.ToInt16(System.Convert.ToDouble(x0) + System.Convert.ToDouble(r0 - r) / 2);
            int y = System.Convert.ToInt16(System.Convert.ToDouble(y0) + System.Convert.ToDouble(r0 - r) / 2);
            zona_des.DrawEllipse(new Pen(culoare_cerc), x + 1, y + 1, r, r);

        }
        public ccon(System.Drawing.Graphics desen, int pozx, int pozy, int raza)
        {
            zona_des = desen;
            x0 = pozx;
            y0 = pozy;
            r0 = raza;
        }
    }