text: function differentSymbolsNaive(s) {
    return new Set(s).size;
  }
  
  ///////////////////////////////////////
  
  function differentSymbolsNaive(s) {
    s = s.split("");
    var distinct = {};
  
    for (x in s) {
      distinct[s[x]] = true;
    }
  
    return Object.keys(distinct).length;
  }
  
  ///////////////////////////////////////
  
  function differentSymbolsNaive(s) {
    t = "";
    s.split``.map(v => t.includes(v) || (t += v));
    return t.length;
  }
  