Drawing

I need to draw eight dots under each other as such:
O O
O O
O O
O O
but i hve code in place that'll only colour the ones i have... any sugeestions??

Code :

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StdDraw.setCanvasSize(1000,400);
		StdDraw.setXscale(0,1000);
		StdDraw.setYscale(1,maxY);
 
		int Xoffset =0;
		int Yoffset = 0;
		char[][] bin = new char [4][2];
		bin[0][0] = binStr.charAt(7);
		bin[0][1] = binStr.charAt(4);	
		bin[1][0] = binStr.charAt(6);
		bin[1][1] = binStr.charAt(3);
		bin[2][0] = binStr.charAt(5);
		bin[2][1] = binStr.charAt(2);
		bin[3][0] = binStr.charAt(1);
		bin[3][1] = binStr.charAt(0);
 
		for (int dotx =0 ;dotx<4; dotx++){
			for (int doty = 0; doty<2; doty++){
				if (bin[dotx][doty] == '1')
				{
					StdDraw.filledCircle(???????,?????,????? );
 
				}

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HELLLLLPPPP!!!!