title: Return the number of times that the string "hello" appears anywhere in the given string
body: <pre><code>public int count(String str){
  
      int count=0;
      int index=str.indexOf("Hello");
      System.out.println(index);
      while(index!=-1)
      {
          index=str.indexOf("Hello",index+1);
  
          count++;
  
      }
      return count;
  
  }
  </code></pre>
  
  <p>Problem when I passes test cases.</p>
  
  <pre><code>Testcase    Pass/Fail   Parameters           Actual Output  Expected Output
  #1             Pass     'Hello how are you'       1               1
  #2             Fail     'HELLO how are you'       0               1
  </code></pre>