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# 1399. Count Largest Group

<https://leetcode.com/problems/count-largest-group>

## Description

Given an integer `n`. Each number from `1` to `n` is grouped according to the sum of its digits.&#x20;

Return how many groups have the largest size.

**Example 1:**

```
**Input:** n = 13
**Output:** 4
**Explanation:** There are 9 groups in total, they are grouped according sum of its digits of numbers from 1 to 13:
[1,10], [2,11], [3,12], [4,13], [5], [6], [7], [8], [9]. There are 4 groups with largest size.
```

**Example 2:**

```
**Input:** n = 2
**Output:** 2
**Explanation:** There are 2 groups [1], [2] of size 1.
```

**Example 3:**

```
**Input:** n = 15
**Output:** 6
```

**Example 4:**

```
**Input:** n = 24
**Output:** 5
```

**Constraints:**

* `1 <= n <= 10^4`

## ac

```java
```