title: Euler 13: Unexpected result while trying to concat multiple String
body: <p>I'm trying to solve <a href="https://projecteuler.net/problem=13" rel="nofollow noreferrer">this problem on euler</a>:</p>
  <blockquote>
  <h3>Large sum</h3>
  <p>Problem 13</p>
  <p>Work out the first ten digits of the sum of the following one-hundred 50-digit numbers.</p>
  <pre><code>37107287533902102798797998220837590246510135740250
  46376937677490009712648124896970078050417018260538
  74324986199524741059474233309513058123726617309629
  ...
  53503534226472524250874054075591789781264330331690
  </code></pre>
  </blockquote>
  <p>I'm trying to concat all the lines into one big chunk of line, however I'm not getting the expected result, can anyone see what I did wrong here?</p>
  <pre><code>var fs  = require(&quot;fs&quot;);
  var total = &quot;\n&quot;;        
  let m1 = fs.readFileSync('lines.txt').toString().split('\n').forEach(line =&gt; {
      total += line;
  })
  console.log(total)
  </code></pre>
  <p>output:</p>
  <blockquote>
  <p>53503534226472524250874054075591789781264330331690</p>
  <p>Process finished with exit code 0</p>
  </blockquote>