/**
 * @Author      KAZE_mae
 * @Website     https://cloudfall.top/
 * @Url         
 * @DateTime    
 */
// #include <bits/stdc++.h>
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;

using ll = long long;
using Ld = long double;
using uint = unsigned int;
using ull = unsigned long long;
template <typename T>
using pair2 = pair<T, T>;
using PII = pair<int, int>;
using PLI = pair<ll, int>;
using PLL = pair<ll, ll>;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) { 
    return (ull)rng() % B; 
}

#define endl '\n'
#define debug(x) cout << #x << " = " << (x) << endl
#define abs(a) ((a) >= 0 ? (a) : -(a))
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define mem(a, b) memset(a, b, sizeof(a))
// #define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))
#define rep(i, a, n) for (int i = a; i <= n; ++i)
#define per(i, n, a) for (int i = n; i >= a; --i)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define lowbit(x) ((x) & (-x))

const int N = 1000005; // 1e6 + 5
const int INF = 0x3f3f3f3f;
const long long LNF = 0x3f3f3f3f3f3f3f3f;
const double EPS = 1e-7;
const double PI = acos(-1.0);
const int MOD = 998244353;

// #define int long long

long long qmi(long long m, long long k, long long p = 2e18) {
    int res = 1 % p, t = m;
    while (k) {
        if (k&1) res = res * t % p;
        t = t * t % p, k >>= 1;
    }
    return res;
}
inline long long gcd(long long a, long long b) {
    return b ? gcd(b, a % b) : a;
}
long long exgcd(long long a, long long b, long long &x, long long &y) {  
    if (!b) { x = 1; y = 0; return a; }  
    int d = exgcd(b, a % b, y, x);
    y -= (a/b) * x;  
    return d;
}

void solve() {
    int n, k, mx = 0, cnt = 1;
    cin>> n >> k;
    vector<int> a(n);
    map<int, int> mp, sum, ct;
    for(int i = 0; i < n; ++ i) {
        cin>> a[i];
        sum[a[i]] ++;
        if(i != 0) if(a[i] == a[i - 1]) ++ cnt;
        else {
            mp[a[i - 1]] = max(cnt, mp[a[i - 1]]);
            cnt = 1;
        }
    }
    mp[a[n - 1]] = max(cnt, mp[a[n - 1]]);
    if(k != 0) {
        for(auto i : mp) {
            mx = max(i.second + sum[i.first + k], mx);
            mx = max(sum[i.first], mx);
        }
        cnt = 1;
        for(int i = 0; i < n; ++ i) {
            if(i != 0)if(a[i] != a[i - 1]) {
                mx = max({mx, 
                    (sum[a[i - 1]] - ct[a[i - 1]] + cnt) + ct[a[i - 1] - k], 
                    ct[a[i - 1]] + (sum[a[i - 1] - k] - ct[a[i - 1] - k])});
                // cout<< i << " " << cnt <<endl;
                cnt = 1;
            }else ++ cnt;
            ct[a[i]] ++;
        }
        mx = max({mx, (sum[a[n - 1]] - ct[a[n - 1]] + cnt) + ct[a[n - 1] - k], ct[a[n - 1]] + (sum[a[n - 1] - k] - ct[a[n - 1] - k])});
    }else for(auto i : mp) mx = max(sum[i.first], mx);
    cout<< mx <<endl;
}
signed main() {
    std::ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    // int _ = 1; cin>> _; while(_ --)
        solve();
  return 0;
}