Problem:
Score : 300 points

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_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.

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

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
int main()
{
    int n,i,j,k,f=0;
    scanf("%d",&n);
    long long int p=0,a[n],d,c=0;
    for(i=0;i<n;i++)
    {
        scanf("%lld",&a[i]);
        c=c+a[i];
        if(i>0){
        if(a[0]==a[i])
            f++;
        }
    }
    if(f==n-1)
        printf("%d",n);
    else
    {
    d=c/(long long int)n;
    for(i=0;i<n;i++)
    {
        if(a[i]==d-1||a[i]==d||a[i]==d-2)
            p++;
    }
    printf("%lld",p);}
 return 0;
}