oter {
	font-family: sans-serif;
	font-size: 16pt;
	font-style: normal;
	padding: 0;
	margin: 0;
	border: 0;
}

canvas { touch-action: none; }
	</style>
	<script language="JavaScript">
const w = 640;
const h = 640;


// Math. aliases
const E = Math.E;			const LN2 = Math.LN2;		const LN10 = Math.LN10;
const LOG10E = Math.LOG10E;	const PI = Math.PI;			const SQRT1_2 = Math.SQRT1_2;
const abs = Math.abs;		const acos = Math.acos;		const acosh = Math.acosh;
const asinh = Math.asinh;	const atan = Math.atan;		const 