JSFiddle - React, Tailwind, and code Playground

HTML

<input readonly value="333" class="static-input">
<input class="nonstatic-input">
<input type="button" onclick="showInput()" value="Go">

CSS

.static-input {
  margin-right: -20px;
  width: 50px;
  border: 0;
}

.nonstatic-input {
  border: 0;
}

JavaScript

function showUserInput () {
  alert('User input: ' + 
        document.querySelector('input.static-input').value +
        document.querySelector('input.nonstatic-input').value
       );
 }
 
 document.querySelector('input[type=button]').addEventListener('click', showUserInput);