#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <vector> #include <map> using namespace std; #define maxN 400007 struct SEG { int st[maxN*4] = {0}; void update(int id, int l, int r, int pos, int val) { if(l==r) { st[id] = val; return; } int mid = (l+r)/2; if(pos <= mid) update(id*2, l, mid, pos, val); else update(id*2+1, mid+1, r, pos, val); st[id] = max(st[id*2+1], st[id*2]); } int query(int id, int l, int r, int u, int v) { if(u > v) return 0; if(l > v || u > r) return 0; if(u <= l && r <= v) return st[id]; int mid = (l+r)/2; int ans1 = query(id*2, l, mid, u, v); int ans2 = query(id*2+1, mid+1, r, u, v); return max(ans1, ans2); } void del() { memset(st, 0, sizeof(st)); } }; vector<int>val; int n, x, m; int a[maxN]; map<int, int> pos; int dp1[maxN]; //normal LIS int dp2[maxN]; //end+x int dp3[maxN]; //rev LIS SEG seg; void readData() { cin >> n >> x; for(int i = 1; i <= n; i++) { cin >> a[i]; val.push_back(a[i]); val.push_back(a[i]+x); } sort(val.begin(), val.end()); val.erase(unique(val.begin(), val.end()), val.end()); m = val.size(); for(int i = 0; i < m; i++) pos[val[i]] = i+1; } void solve() { for(int i = 1; i <= n; i++) { dp1[i] = seg.query(1, 1, m, 1, pos[a[i]]-1)+1; dp2[i] = seg.query(1, 1, m, 1, pos[a[i]+x]-1)+1; seg.update(1, 1, m, pos[a[i]], dp1[i]); } seg.del(); for(int i = n; i >= 1; i--) { dp3[i] = seg.query(1, 1, m, pos[a[i]]+1, m)+1; seg.update(1, 1, m, pos[a[i]], dp3[i]); } int ans = 0; for(int i = 1; i <= n; i++) ans = max(ans, dp2[i] + dp3[i] - 1); cout << ans; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); readData(); solve(); return 0; }