## Always Single

Submit solution

Points:
100

Time limit:
2.0s

Memory limit:
128M

Author:

Problem type

Allowed languages

C, C++, Java, Python

You are given a **sorted** array \(A\) of \(N\) integers. There is special property about \(A\), every element in \(A\) appears exactly twice, except for one element which appears exactly once.

Your task is to find that single element that appears that exactly once.

**Example**

\(N = 5\), \(A = [0,0,1,1,2]\)

except \(2\) every element appears twice, hence answer should be \(2\).

#### Input

First line contains single integer: \(N\).

Second line contains \(N\) integers, where \(i^{th}\) integer is \(A[i]\).

#### Output

Print the single element that appears that exactly once in given array.

#### Constraints

\(1\) \(\leq\) \(N\) \(\leq\) \(10^5\)

\(0\) \(\leq\) \(A[i]\) \(\leq\) \(10^9\)

##### Example

**Input**

```
5
2 2 4 4 1
```

**Output**

`1`

**Note**

You can use this template to submit the solution.

## Comments

the example above is not a

sorted arrayI think they wanted to say duplicates occur together in the array. Only then binary search can be applied