diff --git a/1-js/05-data-types/12-json/1-serialize-object/solution.md b/1-js/05-data-types/12-json/1-serialize-object/solution.md
@@ -2,7 +2,7 @@

```js
let user = {
-  name: "John Smith",
  age: 35
};


diff --git a/1-js/05-data-types/12-json/1-serialize-object/task.md b/1-js/05-data-types/12-json/1-serialize-object/task.md
@@ -2,13 +2,13 @@ importance: 5

---

-# Turn the object into JSON and back

-Turn the `user` into JSON and then read it back into another variable.

```js
let user = {
-  name: "John Smith",
  age: 35
};
```
diff --git a/1-js/05-data-types/12-json/2-serialize-event-circular/task.md b/1-js/05-data-types/12-json/2-serialize-event-circular/task.md
@@ -2,39 +2,39 @@ importance: 5

---

-# Exclude backreferences

-In simple cases of circular references, we can exclude an offending property from serialization by its name.

-But sometimes we can't just use the name, as it may be used both in circular references and normal properties. So we can check the property by its value.

-Write `replacer` function to stringify everything, but remove properties that reference `meetup`:

```js run
let room = {
  number: 23
};

let meetup = {
-  title: "Conference",
-  occupiedBy: [{name: "John"}, {name: "Alice"}],
  place: room
};

*!*
-// circular references
room.occupiedBy = meetup;
meetup.self = meetup;
*/!*

alert( JSON.stringify(meetup, function replacer(key, value) {
-  /* your code */
}));

-/* result should be:
{
-  "title":"Conference",
-  "occupiedBy":[{"name":"John"},{"name":"Alice"}],
  "place":{"number":23}
}
*/
-Original file line number
+Diff line change
@@ Expand Up / @@ -2,7 +2,7 @@ @@
     ```js
     let user = {
-      name: "John Smith",
       age: 35
     };
@@ Expand Down @@