title: Bracket error in c "error: expected identifier or '(' {"
body: <p>I'm working on a problem set for CS50 in C but I keep getting an error <code>readability.c:11:1: error: expected identifier or '(' {</code> and I'm not sure what's wrong. Any help would be much appreciated.</p>
  <pre><code>#include &lt;cs50.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;string.h&gt;
  #include &lt;ctype.h&gt;
  
  int count_letters(string text);
  
  int main(void);
  {
      string paragraph = get_string(&quot;Input text: &quot;);
  
      count_letters(paragraph);
  
      int L = 0;
      int S = 0;
  
      int index = 0.0588 * L - 0.296 * S - 15.8;
  
      printf(&quot;%i&quot;, index);
  }
  
  int count_letters(string text)
  {
      int letters = 0;
  
      for (int i = 0, length = strlen(text); i &lt; length; i++)
          if isalpha(text[i]) {
              letters + 1
          }
  
      return letters;
  }
  </code></pre>