Determine whether or not an array $A$ of length $n$ is a palindrome (reads the same backwards as forwards, for example `32123`).
### Input
- The first line contains an integer $n$.
- The second line contains $n$ integers $A_i$.
### Output
- Print `YES` if $A$ is a Palindrome, `NO` otherwise.
### Constraints
- $1 \le n \le 1000$.
- $|A_i| \le 1000 $.
### Example
Input:
```
4
1 2 2 1
```
Output:
```
YES
```
