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+<title>Day 9 - Advent of Code 2017</title>
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+Oh, hello! Funny seeing you here.
+
+I appreciate your enthusiasm, but you aren't going to find much down here.
+There certainly aren't clues to any of the puzzles. The best surprises don't
+even appear in the source until you unlock them for real.
+
+Please be careful with automated requests; I'm not Google, and I can only take
+so much traffic. Please be considerate so that everyone gets to play.
+
+If you're curious about how Advent of Code works, it's running on some custom
+Perl code. Other than a few integrations (auth, analytics, ads, social media),
+I built the whole thing myself, including the design, animations, prose, and
+all of the puzzles.
+
+The puzzles probably took the longest; the easiest ones took an hour or two
+each, but the harder ones took 4-5 hours, and a few even longer than that. A
+lot of effort went into building this thing - I hope you're enjoying playing it
+as much as I enjoyed making it for you!
+
+If you'd like to hang out, I'm @ericwastl on Twitter.
+
+- Eric Wastl
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+-->
+<body>
+<header><div><h1 class="title-global"><a href="/">Advent of Code</a></h1><nav><ul><li><a href="/2017/about">[About]</a></li><li><a href="/2017/support">[AoC++]</a></li><li><a href="/2017/events">[Events]</a></li><li><a href="/2017/settings">[Settings]</a></li><li><a href="/2017/auth/logout">[Log Out]</a></li></ul></nav><div class="user">Neil Smith <span class="supporter">(AoC++)</span> <span class="star-count">18*</span></div></div><div><h1 class="title-event"> <span class="title-event-wrap">/*</span><a href="/2017">2017</a><span class="title-event-wrap">*/</span></h1><nav><ul><li><a href="/2017">[Calendar]</a></li><li><a href="/2017/leaderboard">[Leaderboard]</a></li><li><a href="/2017/stats">[Stats]</a></li><li><a href="/2017/sponsors">[Sponsors]</a></li></ul></nav></div></header>
+
+<div id="sidebar">
+<div id="sponsor"><div class="quiet">Our <a href="/2017/sponsors">sponsors</a> help make Advent of Code possible:</div><p><a href="http://winton.com/" target="_blank" onclick="if(ga)ga('send','event','sponsor','click',this.href);" rel="noopener">Winton</a> - a data science and investment management company</p></div>
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+
+<main>
+<article class="day-desc"><h2>--- Day 9: Stream Processing ---</h2><p>A large stream blocks your path. According to the locals, it's not safe to <span title=""Don't cross the streams!", they yell, even though there's only one. They seem to think they're hilarious.">cross the stream</span> at the moment because it's full of <em>garbage</em>. You look down at the stream; rather than water, you discover that it's a <em>stream of characters</em>.</p>
+<p>You sit for a while and record part of the stream (your puzzle input). The characters represent <em>groups</em> - sequences that begin with <code>{</code> and end with <code>}</code>. Within a group, there are zero or more other things, separated by commas: either another <em>group</em> or <em>garbage</em>. Since groups can contain other groups, a <code>}</code> only closes the <em>most-recently-opened unclosed group</em> - that is, they are nestable. Your puzzle input represents a single, large group which itself contains many smaller ones.</p>
+<p>Sometimes, instead of a group, you will find <em>garbage</em>. Garbage begins with <code><</code> and ends with <code>></code>. Between those angle brackets, almost any character can appear, including <code>{</code> and <code>}</code>. <em>Within</em> garbage, <code><</code> has no special meaning.</p>
+<p>In a futile attempt to clean up the garbage, some program has <em>canceled</em> some of the characters within it using <code>!</code>: inside garbage, <em>any</em> character that comes after <code>!</code> should be <em>ignored</em>, including <code><</code>, <code>></code>, and even another <code>!</code>.</p>
+<p>You don't see any characters that deviate from these rules. Outside garbage, you only find well-formed groups, and garbage always terminates according to the rules above.</p>
+<p>Here are some self-contained pieces of garbage:</p>
+<ul>
+<li><code><></code>, empty garbage.</li>
+<li><code><random characters></code>, garbage containing random characters.</li>
+<li><code><<<<></code>, because the extra <code><</code> are ignored.</li>
+<li><code><{!>}></code>, because the first <code>></code> is canceled.</li>
+<li><code><!!></code>, because the second <code>!</code> is canceled, allowing the <code>></code> to terminate the garbage.</li>
+<li><code><!!!>></code>, because the second <code>!</code> and the first <code>></code> are canceled.</li>
+<li><code><{o"i!a,<{i<a></code>, which ends at the first <code>></code>.</li>
+</ul>
+<p>Here are some examples of whole streams and the number of groups they contain:</p>
+<ul>
+<li><code>{}</code>, <code>1</code> group.</li>
+<li><code>{{{}}}</code>, <code>3</code> groups.</li>
+<li><code>{{},{}}</code>, also <code>3</code> groups.</li>
+<li><code>{{{},{},{{}}}}</code>, <code>6</code> groups.</li>
+<li><code>{<{},{},{{}}>}</code>, <code>1</code> group (which itself contains garbage).</li>
+<li><code>{<a>,<a>,<a>,<a>}</code>, <code>1</code> group.</li>
+<li><code>{{<a>},{<a>},{<a>},{<a>}}</code>, <code>5</code> groups.</li>
+<li><code>{{<!>},{<!>},{<!>},{<a>}}</code>, <code>2</code> groups (since all but the last <code>></code> are canceled).</li>
+</ul>
+<p>Your goal is to find the total score for all groups in your input. Each group is assigned a <em>score</em> which is one more than the score of the group that immediately contains it. (The outermost group gets a score of <code>1</code>.)</p>
+<ul>
+<li><code>{}</code>, score of <code>1</code>.</li>
+<li><code>{{{}}}</code>, score of <code>1 + 2 + 3 = 6</code>.</li>
+<li><code>{{},{}}</code>, score of <code>1 + 2 + 2 = 5</code>.</li>
+<li><code>{{{},{},{{}}}}</code>, score of <code>1 + 2 + 3 + 3 + 3 + 4 = 16</code>.</li>
+<li><code>{<a>,<a>,<a>,<a>}</code>, score of <code>1</code>.</li>
+<li><code>{{<ab>},{<ab>},{<ab>},{<ab>}}</code>, score of <code>1 + 2 + 2 + 2 + 2 = 9</code>.</li>
+<li><code>{{<!!>},{<!!>},{<!!>},{<!!>}}</code>, score of <code>1 + 2 + 2 + 2 + 2 = 9</code>.</li>
+<li><code>{{<a!>},{<a!>},{<a!>},{<ab>}}</code>, score of <code>1 + 2 = 3</code>.</li>
+</ul>
+<p><em>What is the total score</em> for all groups in your input?</p>
+</article>
+<p>Your puzzle answer was <code>11089</code>.</p><article class="day-desc"><h2>--- Part Two ---</h2><p>Now, you're ready to remove the garbage.</p>
+<p>To prove you've removed it, you need to count all of the characters within the garbage. The leading and trailing <code><</code> and <code>></code> don't count, nor do any canceled characters or the <code>!</code> doing the canceling.</p>
+<ul>
+<li><code><></code>, <code>0</code> characters.</li>
+<li><code><random characters></code>, <code>17</code> characters.</li>
+<li><code><<<<></code>, <code>3</code> characters.</li>
+<li><code><{!>}></code>, <code>2</code> characters.</li>
+<li><code><!!></code>, <code>0</code> characters.</li>
+<li><code><!!!>></code>, <code>0</code> characters.</li>
+<li><code><{o"i!a,<{i<a></code>, <code>10</code> characters.</li>
+</ul>
+<p><em>How many non-canceled characters are within the garbage</em> in your puzzle input?</p>
+</article>
+<p>Your puzzle answer was <code>5288</code>.</p><p class="day-success">Both parts of this puzzle are complete! They provide two gold stars: **</p>
+<p>At this point, you should <a href="/2017">return to your advent calendar</a> and try another puzzle.</p>
+<p>If you still want to see it, you can <a href="9/input" target="_blank">get your puzzle input</a>.</p>
+<p>You can also <span class="share">[Share<span class="share-content">on
+ <a href="https://twitter.com/intent/tweet?text=I%27ve+completed+%22Stream+Processing%22+%2D+Day+9+%2D+Advent+of+Code+2017&url=http%3A%2F%2Fadventofcode%2Ecom%2F2017%2Fday%2F9&related=ericwastl&hashtags=AdventOfCode" target="_blank">Twitter</a>
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+></span>]</span> this puzzle.</p>
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