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
#include <bits/stdc++.h>

using namespace std;

int n;
int a[100001];
int main() {
  cin >> n;
  for(int i = 0; i < n; i++) {
    int x;
    cin >> x;
    if(x > 0) a[x-1]++;
    a[x]++;
    a[x+1]++;
  }
  int ans = 0;
  for(int i = 0; i < 100001; i++) {
    ans = max(ans,a[i]);
  }

  cout << ans << endl;
}

  
  
