#include <bits/stdc++.h>
#define VuDucNam ios_base::sync_with_stdio(false);
#define Lop9a6 cin.tie(NULL);
#define THCSPhamVanDong cout.tie(NULL);
#define ll long long
#define el cout << '\n'
#define sz(a) (ll) a.size()
#define all(a) a.begin(), a.end()
#define fi first
#define se second
#define fill(a, x) memset(a, x, sizeof(a))
#define file(name)                         \
    if (fopen(name ".INO", "r"))           \
    {                                      \
        freopen(name ".INP", "r", stdin);  \
        freopen(name ".OUT", "w", stdout); \
    }
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define RUNTIME cerr << "\nRuntime: " << TIME << "s.\n"

using namespace std;

const int N5 = 1e5 + 5;
const ll MOD = 1e9 + 7;
const ll inf = LLONG_MAX;

int n,k,a[1005],dp[1005],ans=0;

void solve()
{
    cin >> n >> k;
    for(int i=1;i<=n;++i){
        cin >> a[i];
        dp[i]=1;
        for(int j=1;j<i;++j){
            if(a[j]+k==a[i]){
                dp[i]=max(dp[i],dp[j]+1);
            }
        }
        ans=max(ans,dp[i]);
    }
    cout << ans;
    el;
}

int main()
{
    VuDucNam Lop9a6 THCSPhamVanDong
    file("BAI5");
    solve();
    RUNTIME;
    return 0;
}