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### Title

### Problem Statement

You are given an integer sequence of length `N`, `a _{1},a_{2},...,a_{N}`.

For each `1≤i≤N`, you have three choices: add `1` to `a _{i}`, subtract

`1`from

`a`or do nothing.

_{i}After these operations, you select an integer `X` and count the number of `i` such that `a _{i}=X`.

Maximize this count by making optimal choices.

### Constraints

`1≤N≤10`^{5}`0≤a`_{i}<10^{5}(1≤i≤N)`a`is an integer._{i}

### Input

The input is given from Standard Input in the following format:

Na_{1}a.._{2}a_{N}

### Output

Print the maximum possible number of `i` such that `a _{i}=X`.

### Sample Input 1

7 3 1 4 1 5 9 2

### Sample Output 1

4

For example, turn the sequence into `2,2,3,2,6,9,2` and select `X=2` to obtain `4`, the maximum possible count.

### Sample Input 2

10 0 1 2 3 4 5 6 7 8 9

### Sample Output 2

3

### Sample Input 3

1 99999

### Sample Output 3

1

### Tags

### Subtasks and Limits

Subtask | Score | #TC | Time | Memory | Scoring |
---|---|---|---|---|---|

1 | 100 | 9 | 1s | 256MB | Minimum |

2 | 0 | 3 | 1s | 256MB | Minimum |

### Judge Compile Command

g++-7 ans.cpp -o together -Wall -static -O2 -lm -m64 -s -w -std=gnu++17 -fmax-errors=512