#include<bits/stdc++.h>
#define ios ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
using namespace std;using ll = long long;using PLL = pair<ll,ll>;
const ll MAX = 1e18;const ll MIN = -1e18;const ll INF=0x3f3f3f3f;
const ll Q = 6e6+9;const ll MOD = 1e9 + 7;
ll a[Q];
vector<ll> d[Q];
set<ll> st;
void solve(){
   ll n,k;cin>>n>>k;
   ll p=2000050;ll ans=0;
   for (ll i = 1; i <= n; i++)
    {
        cin>>a[i];
        st.insert(a[i]);
        d[a[i]+p].push_back(i);
        ans=max(ans,(ll)d[a[i]+p].size());
    }
   for(auto i:st){
    if(d[i-k+p].size()<=0) continue;
    vector<ll> v;
    ll l=0,r=0;
    while(l<d[i+p].size() or r<d[i-k+p].size())
    {
        if(l<d[i+p].size() and r<d[i-k+p].size()){
            if(d[i+p][l]<d[i-k+p][r]){
                v.push_back(-1);
                l++;
            }else{
                v.push_back(1);
                r++;
            }
            continue;
        }
        if(l>=d[i+p].size()) v.push_back(1),r++;
        if(r>=d[i-k+p].size()) v.push_back(-1),l++;
    }
    ll m=v.size();
    ll sum=1;
    ll mi=0;ll now=0;
    // dp[i] = Math.max(arr[i] , do[i - 1] + arr[i]])
    for (int i = 0 ; i < m ; i++){
        mi = max(v[i] , mi + v[i]);
        sum = max(sum , mi);
    
    }

    ans=max(ans,sum+(ll)d[i+p].size());
   }
   cout<<ans<<"\n";

}
int main(){
    ios;ll _=1;//cin>>_;
    while (_--)solve();
    return 0;
}