title: Intellij doesn't recognize class
body: <p>i was doing some homework in java but intellij doesn't recognize my class. It recognize the main class but it recognize the other class only on the first execution, whenever i modify the code and rebuild it intellij doesn't recognize the other class. I thought it was a jdk problem so i've downloaded an open source jdk but the problem persits. I've found  no solutions yet, neither in the intellij forum. It sees the class only if i do a refactor but that's annoying. Mine intellij is up to date(7/5/19).</p>
  
  <p>You can see in the pictures that intellij doesn't give me any problem on the syntax but it says that he cannot resolve "Matrix".</p>
  
  <p><img src="https://i.stack.imgur.com/XunrP.png" alt="">
  <img src="https://i.stack.imgur.com/UF4mX.png" alt=""></p>