title: Remove and Add letters in Strings
body: <p>I am trying to solve a problem in C#. </p>
  
  <p>Here is the task:</p>
  
  <blockquote>
    <ul>
    <li>If a word <em>begins</em> with a <em>vowel</em> (a, e, i, o, u or A, E, I, O, U), <em>remove</em>
    the first letter and append it to the end, then add <strong>"che"</strong>. If you have
    the word “orange” It translates to “rangeoche”</li>
    <li>If a word <em>begins</em> with a <em>consonant</em> (i.e. not a vowel), append <strong>"che"</strong> to the end of the word. For example, the word "chicken" becomes
    "chickenche".</li>
    <li>If the word has <em>even number</em> of letters append one more <strong>"e"</strong> to the end of it. </li>
    </ul>
    
    <p>Print the translated sentence.</p>
  </blockquote>
  
  <p><strong>Example:</strong></p>
  
  <pre><code>Hello there Amy
  </code></pre>
  
  <p><strong>Output:</strong></p>
  
  <pre><code>Helloche thereche myAche
  </code></pre>
  
  <p>Here is what I have done so far :</p>
  
  <pre><code>        string Sentence = Console.ReadLine();
          string[] output = Sentence.Split(' ');
          char letter;
          string che = "che";
          StringBuilder sb = new StringBuilder(Sentence);
          foreach (string s in output)
          {
              letter = s[0];
  
              if (letter == 'a' || letter == 'A' || letter == 'e' || letter == 'E' || letter == 'i'
              || letter == 'I' || letter == 'o' || letter == 'O' || letter == 'u' || letter == 'U')
              {
               //  Console.WriteLine("first char of the word is a vowel");
              }
              else
              {
                  sb.Insert(s.Length,che);
                //  Console.WriteLine("first char of a word is a consonant");
              }
  
              if (s.Length % 2 == 0)
              {
                //  Console.WriteLine("the word has even numbers of letters");
              }
              //Console.WriteLine(firstchar);
              int currentWordLength = s.Length;
  
          }
          Console.WriteLine(sb);
  </code></pre>
  
  <p>The problem is I cannot add <code>"che"</code> or remove vowels of words because the <em>index is moving</em> due to those changes. I can only change the first word. My ifs are correct because if I uncomment the <code>Console.Writelines</code> they scan through each word.
  I am just struggling with the adding/removing of each word. Can you please point me to the right direction?</p>