p03613 AtCoder Regular Contest 082 - Together
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_i or do nothing.

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_i is an integer.

Input

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


N
a_1 a_2 .. a_N


Output

Print the maximum possible number of i such that a_i=X.

Examples

Input

7
3 1 4 1 5 9 2


Output

4


Input

10
0 1 2 3 4 5 6 7 8 9


Output

3


Input

1
99999


Output

1
```python
n = int(input())
ar = [int(x) for x in input().split()]

cnt = {}
for x in ar:
        def add(x):
                if x in cnt:
                        cnt[x] += 1
                else:
                        cnt[x] = 1
        add(x-1)
        add(x)
        add(x+1)

counts = map(lambda x: x[1], cnt.items())
ans = max(counts)

print(ans)

```