Не могу понять как пользоваться FloodFill

private: System::Void __fastcall button1_Click(System::Object^ sender, System::EventArgs^ e) {
        Bitmap^ bmp = gcnew Bitmap(pictureBox1->Width, pictureBox1->Height);
        Graphics^ graph = Graphics::FromImage(bmp);
        float R = Convert::ToInt32(textBox3->Text);
        float X = pictureBox1->Width / 2 - R;
        float Y = pictureBox1->Height / 2 - R;
            graph->DrawEllipse(Pens::Black, X, Y, R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X - R, Y, R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X + R, Y, R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X, Y - R, R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X, Y + R, R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X - (0.87*R), Y + (0.5*R), R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X + (0.87*R), Y + (0.5*R), R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X - (0.87*R), Y - (0.5*R), R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X + (0.87*R), Y - (0.5*R), R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X + (0.5*R), Y - (0.87*R), R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X + (0.5*R), Y + (0.87*R), R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X - (0.5*R), Y - (0.87*R), R * 2, R * 2);
            graph->DrawEllipse(Pens::Black, X - (0.5*R), Y + (0.87*R), R * 2, R * 2);
    }