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<a name="Blocking"></a>
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<a name="Blocking-1"></a>
<h3 class="subsection">2.2.2 Blocking</h3>

<p>After the bit string is obtained as described above, it is grouped into
blocks of six. Continuing with the example, the string
</p>
<table><tr><td>&nbsp;</td><td><pre class="example">111111101011110010001001100010100010100100100
</pre></td></tr></table>

<p>would be grouped as
</p>
<table><tr><td>&nbsp;</td><td><pre class="example">111111 101011 110010 001001 100010 100010 100100 100
</pre></td></tr></table>

<p>Because the number of bits isn&rsquo;t a multiple of six, the last group has to
be padded with zeros, to give
</p>
<table><tr><td>&nbsp;</td><td><pre class="example">111111 101011 110010 001001 100010 100010 100100 100000
</pre></td></tr></table>

<p>Each of these six bit substrings is then treated as a binary number,
with the most significant bit on the left. The numbers expressed in
decimal are
</p>
<table><tr><td>&nbsp;</td><td><pre class="example">63 43 50 9 34 34 36 32
</pre></td></tr></table>

<a name="index-character-codes"></a>
<p>The character codes for the characters to be written are obtained by
adding sixty to each of these numbers, so as to ensure that they will be
printable characters. The resulting character codes are
</p>
<table><tr><td>&nbsp;</td><td><pre class="example">123 103 110 69 94 94 96 92
</pre></td></tr></table>

<p>which implies that the tree in the example could be written to a file as
<code>{gnE^^`\</code>.
</p>
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