New puzzle based on codeforces 133 A (harder)

[akalai]

def sat(s: str):
    """
    Find a string with certain characters, simple codeforces problem

    Inspired by [Codeforces Problem 133 A](https://codeforces.com/problemset/problem/133/A)
    """
    for c in ["H", "Q", "9"]:
        if s.count(c) != 17:
            return False
    return True

Solvers, post your solutions in the comments using the following formatting:

<details><summary>Reveal solution</summary>

```python
def sol():
    return "world"  # replace with your solution
```
</details>

[sofiavempala]

Reveal solution

def sol():
    return "world"  # "HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9HQ9H9Q"

[masak]

Reveal solution

def sol():
    return "HQ9" * 17