Contest Duration: ~ (local time) (100 minutes) Back to Home
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Time Limit: 2 sec / Memory Limit: 1024 MB

### 制約

• 1 \leq X \leq 100
• 0 \leq N \leq 100
• 1 \leq p_i \leq 100
• p_1, \ldots, p_N はすべて異なる。
• 入力中のすべての値は整数である。

### 入力

X N
p_1 ... p_N


### 入力例 1

6 5
4 7 10 6 5


### 出力例 1

8


### 入力例 2

10 5
4 7 10 6 5


### 出力例 2

9


### 入力例 3

100 0



### 出力例 3

100


N = 0 の場合、入力の 2 行目は空行となります。また、この場合のように、X 自身も答えとなりえます。

Score : 300 points

### Problem Statement

Given are an integer X and an integer sequence of length N: p_1, \ldots, p_N.

Among the integers not contained in the sequence p_1, \ldots, p_N (not necessarily positive), find the integer nearest to X, that is, find the integer whose absolute difference with X is the minimum. If there are multiple such integers, report the smallest such integer.

### Constraints

• 1 \leq X \leq 100
• 0 \leq N \leq 100
• 1 \leq p_i \leq 100
• p_1, \ldots, p_N are all distinct.
• All values in input are integers.

### Input

Input is given from Standard Input in the following format:

X N
p_1 ... p_N


### Sample Input 1

6 5
4 7 10 6 5


### Sample Output 1

8


Among the integers not contained in the sequence 4, 7, 10, 6, 5, the one nearest to 6 is 8.

### Sample Input 2

10 5
4 7 10 6 5


### Sample Output 2

9


Among the integers not contained in the sequence 4, 7, 10, 6, 5, the ones nearest to 10 are 9 and 11. We should print the smaller one, 9.

### Sample Input 3

100 0



### Sample Output 3

100


When N = 0, the second line in the input will be empty. Also, as seen here, X itself can be the answer.