Llama 4 Scout 17B 16E Instruct vs Kimi K2 Turbo

# Challenge \#10: 📨 Depth of Christmas magic 





EASY

# 🎄 Depth of Christmas Magic

At the North Pole, Santa Claus is reviewing the magical letters 📩✨ he receives from children all over the world. These letters use an ancient Christmas language in which the brackets `[` and `]` represent the intensity of the wish.

The deeper the nesting of the brackets, the stronger the wish. Your mission is to find out the **maximum depth** at which the `[]` are nested.

But be careful! Some letters may be **poorly written**. If the brackets are not properly balanced (if one closes before it opens, there are extra closing brackets, or closing brackets are missing), the letter is invalid and you must return `-1`.

```javascript
maxDepth('[]') // -> 1
maxDepth('[[]]') // -> 2
maxDepth('[][]') // -> 1
maxDepth('[[][]]') // -> 2
maxDepth('[[[]]]') // -> 3
maxDepth('[][[]][]') // -> 2

maxDepth('][') // -> -1 (closes before opening)\
maxDepth('[[[') // -> -1 (missing closing brackets)\
maxDepth('[]]]') // -> -1 (extra closing brackets)\
maxDepth('[][][') // -> -1 (one remains unclosed)\
```