CF296A.Yaroslav and Permutations

普及/提高-

通过率：0%

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题目描述

Yaroslav has an array that consists of $n$ integers. In one second Yaroslav can swap two neighboring array elements. Now Yaroslav is wondering if he can obtain an array where any two neighboring elements would be distinct in a finite time.

Help Yaroslav.

输入格式

The first line contains integer $n$ $(1<=n<=100)$ — the number of elements in the array. The second line contains $n$ integers $a_{1},a_{2},...,a_{n}$ $(1<=a_{i}<=1000)$ — the array elements.

输出格式

In the single line print "YES" (without the quotes) if Yaroslav can obtain the array he needs, and "NO" (without the quotes) otherwise.

输入输出样例

输入#1
```
1
1
```
输出#1
```
YES
```
输入#2
```
3
1 1 2
```
输出#2
```
YES
```
输入#3
```
4
7 7 7 7
```
输出#3
```
NO
```

说明/提示

In the first sample the initial array fits well.

In the second sample Yaroslav can get array: $1$ , $2$ , $1$ . He can swap the last and the second last elements to obtain it.

In the third sample Yarosav can't get the array he needs.

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