Title
Problem Statement
You are given an integer sequence of length N, a1,a2,...,aN.
For each 1≤i≤N, you have three choices: add 1 to ai, subtract 1 from ai or do nothing.
After these operations, you select an integer X and count the number of i such that ai=X.
Maximize this count by making optimal choices.
Constraints
- 1≤N≤105
- 0≤ai<105 (1≤i≤N)
- ai is an integer.
Input
The input is given from Standard Input in the following format:
N
a1 a2 .. aN
Output
Print the maximum possible number of i such that ai=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