# 0660. Remove 9

<https://leetcode.com/problems/remove-9>

## Description

Start from integer `1`, remove any integer that contains `9` such as `9`, `19`, `29`...

Now, you will have a new integer sequence `[1, 2, 3, 4, 5, 6, 7, 8, 10, 11, ...]`.

Given an integer `n`, return *the* `nth` (**1-indexed**) integer in the new sequence.

**Example 1:**

```
**Input:** n = 9
**Output:** 10
```

**Example 2:**

```
**Input:** n = 10
**Output:** 11
```

**Constraints:**

* `1 <= n <= 8 * 108`

## ac

```java
```