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+<title>Day 7 - Advent of Code 2020</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 a massive company, 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, social media), I
+built the whole thing myself, including the design, animations, prose, and all
+of the puzzles.
+
+The puzzles are most of the work; preparing a new calendar and a new set of
+puzzles each year takes all of my free time for 4-5 months. 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="/2020/about">[About]</a></li><li><a href="/2020/events">[Events]</a></li><li><a href="https://teespring.com/stores/advent-of-code" target="_blank">[Shop]</a></li><li><a href="/2020/settings">[Settings]</a></li><li><a href="/2020/auth/logout">[Log Out]</a></li></ul></nav><div class="user">Neil Smith <a href="/2020/support" class="supporter-badge" title="Advent of Code Supporter">(AoC++)</a> <span class="star-count">14*</span></div></div><div><h1 class="title-event"> <span class="title-event-wrap">$year=</span><a href="/2020">2020</a><span class="title-event-wrap">;</span></h1><nav><ul><li><a href="/2020">[Calendar]</a></li><li><a href="/2020/support">[AoC++]</a></li><li><a href="/2020/sponsors">[Sponsors]</a></li><li><a href="/2020/leaderboard">[Leaderboard]</a></li><li><a href="/2020/stats">[Stats]</a></li></ul></nav></div></header>
+
+<div id="sidebar">
+<div id="sponsor"><div class="quiet">Our <a href="/2020/sponsors">sponsors</a> help make Advent of Code possible:</div><div class="sponsor"><a href="https://whimsical.com/advent-of-code-2020-get-unstuck-with-whimsical-7hoTGmwqttswvigWHqAgpU@2Ux7TurymLzKXw2f4wcD" target="_blank" onclick="if(ga)ga('send','event','sponsor','sidebar',this.href);" rel="noopener">Whimsical</a> - Brainstorm visually. FAST. Stuck on a puzzle? We can help!</div></div>
+</div><!--/sidebar-->
+
+<main>
+<script>window.addEventListener('click', function(e,s,r){if(e.target.nodeName==='CODE'&&e.detail===3){s=window.getSelection();s.removeAllRanges();r=document.createRange();r.selectNodeContents(e.target);s.addRange(r);}});</script>
+<article class="day-desc"><h2>--- Day 7: Handy Haversacks ---</h2><p>You land at the regional airport in time for your next flight. In fact, it looks like you'll even have time to grab some food: all flights are currently delayed due to <em>issues in luggage processing</em>.</p>
+<p>Due to recent aviation regulations, many rules (your puzzle input) are being enforced about bags and their contents; bags must be color-coded and must contain specific quantities of other color-coded bags. Apparently, nobody responsible for these regulations considered how long they would take to enforce!</p>
+<p>For example, consider the following rules:</p>
+<pre><code>light red bags contain 1 bright white bag, 2 muted yellow bags.
+dark orange bags contain 3 bright white bags, 4 muted yellow bags.
+bright white bags contain 1 shiny gold bag.
+muted yellow bags contain 2 shiny gold bags, 9 faded blue bags.
+shiny gold bags contain 1 dark olive bag, 2 vibrant plum bags.
+dark olive bags contain 3 faded blue bags, 4 dotted black bags.
+vibrant plum bags contain 5 faded blue bags, 6 dotted black bags.
+faded blue bags contain no other bags.
+dotted black bags contain no other bags.
+</code></pre>
+<p>These rules specify the required contents for 9 bag types. In this example, every <code>faded blue</code> bag is empty, every <code>vibrant plum</code> bag contains 11 bags (5 <code>faded blue</code> and 6 <code>dotted black</code>), and so on.</p>
+<p>You have a <code><em>shiny gold</em></code> bag. If you wanted to carry it in at least one other bag, how many different bag colors would be valid for the outermost bag? (In other words: how many colors can, eventually, contain at least one <code>shiny gold</code> bag?)</p>
+<p>In the above rules, the following options would be available to you:</p>
+<ul>
+<li>A <code>bright white</code> bag, which can hold your <code>shiny gold</code> bag directly.</li>
+<li>A <code>muted yellow</code> bag, which can hold your <code>shiny gold</code> bag directly, plus some other bags.</li>
+<li>A <code>dark orange</code> bag, which can hold <code>bright white</code> and <code>muted yellow</code> bags, either of which could then hold your <code>shiny gold</code> bag.</li>
+<li>A <code>light red</code> bag, which can hold <code>bright white</code> and <code>muted yellow</code> bags, either of which could then hold your <code>shiny gold</code> bag.</li>
+</ul>
+<p>So, in this example, the number of bag colors that can eventually contain at least one <code>shiny gold</code> bag is <code><em>4</em></code>.</p>
+<p><em>How many bag colors can eventually contain at least one <code>shiny gold</code> bag?</em> (The list of rules is quite long; make sure you get all of it.)</p>
+</article>
+<p>Your puzzle answer was <code>242</code>.</p><article class="day-desc"><h2 id="part2">--- Part Two ---</h2><p>It's getting pretty expensive to fly these days - not because of ticket prices, but because of the ridiculous number of bags you need to buy!</p>
+<p>Consider again your <code>shiny gold</code> bag and the rules from the above example:</p>
+<ul>
+<li><code>faded blue</code> bags contain <code>0</code> other bags.</li>
+<li><code>dotted black</code> bags contain <code>0</code> other bags.</li>
+<li><code>vibrant plum</code> bags contain <code>11</code> other bags: 5 <code>faded blue</code> bags and 6 <code>dotted black</code> bags.</li>
+<li><code>dark olive</code> bags contain <code>7</code> other bags: 3 <code>faded blue</code> bags and 4 <code>dotted black</code> bags.</li>
+</ul>
+<p>So, a single <code>shiny gold</code> bag must contain 1 <code>dark olive</code> bag (and the 7 bags within it) plus 2 <code>vibrant plum</code> bags (and the 11 bags within <em>each</em> of those): <code>1 + 1*7 + 2 + 2*11</code> = <code><em>32</em></code> bags!</p>
+<p>Of course, the actual rules have a <span title="100%">small</span> chance of going several levels deeper than this example; be sure to count all of the bags, even if the nesting becomes topologically impractical!</p>
+<p>Here's another example:</p>
+<pre><code>shiny gold bags contain 2 dark red bags.
+dark red bags contain 2 dark orange bags.
+dark orange bags contain 2 dark yellow bags.
+dark yellow bags contain 2 dark green bags.
+dark green bags contain 2 dark blue bags.
+dark blue bags contain 2 dark violet bags.
+dark violet bags contain no other bags.
+</code></pre>
+<p>In this example, a single <code>shiny gold</code> bag must contain <code><em>126</em></code> other bags.</p>
+<p><em>How many individual bags are required inside your single <code>shiny gold</code> bag?</em></p>
+</article>
+<p>Your puzzle answer was <code>176035</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="/2020">return to your Advent calendar</a> and try another puzzle.</p>
+<p>If you still want to see it, you can <a href="7/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+%22Handy+Haversacks%22+%2D+Day+7+%2D+Advent+of+Code+2020&url=https%3A%2F%2Fadventofcode%2Ecom%2F2020%2Fday%2F7&related=ericwastl&hashtags=AdventOfCode" target="_blank">Twitter</a>
+ <a href="javascript:void(0);" onclick="var mastodon_instance=prompt('Mastodon Instance / Server Name?'); if(typeof mastodon_instance==='string' && mastodon_instance.length){this.href='https://'+mastodon_instance+'/share?text=I%27ve+completed+%22Handy+Haversacks%22+%2D+Day+7+%2D+Advent+of+Code+2020+%23AdventOfCode+https%3A%2F%2Fadventofcode%2Ecom%2F2020%2Fday%2F7'}else{return false;}" target="_blank">Mastodon</a
+></span>]</span> this puzzle.</p>
+</main>
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