Try without glue

src/calculator/index.html

@@ -3,7 +3,7 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <link rel="icon" href="data:,">
-    <script src="./script.js" defer></script>
+    <script src="./script.js"></script>
     <title>dn724</title>
 
     <style>

src/calculator/script.js

@@ -15,6 +15,7 @@ function calculate(el) {
     result.innerText = cand;
 }
 
+// https://github.com/bryc/code/blob/master/jshash/experimental/cyrb53.js
 const cyrb53 = (str, seed = 0) => {
     let h1 = 0xdeadbeef ^ seed, h2 = 0x41c6ce57 ^ seed;
     for (let i = 0, ch; i < str.length; i++) {
@@ -28,6 +29,4 @@ const cyrb53 = (str, seed = 0) => {
     h2 ^= Math.imul(h1 ^ (h1 >>> 13), 3266489909);
     
     return 4294967296 * (2097151 & h2) + (h1 >>> 0);
-};
-
-calculate(result); // this is necessary for parcel
+};