#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <queue>
#include <cmath>
#include <set>
typedef long long llong;
const int MAXN = 300000 + 10;
const int INF = 1e9;
int n, d;
struct SegmentTree
{
struct Node
{
int length;
int prefixOnes;
int suffixOnes;
int maxOnes;
int maxDP;
Node()
{
prefixOnes = suffixOnes = maxOnes = maxDP = length = 0;
}
friend Node operator + (const Node &left, const Node &right)
{
Node res;
res.length = left.length + right.length;
res.prefixOnes = left.prefixOnes;
if (left.prefixOnes == left.length) res.prefixOnes = left.length + right.prefixOnes;
res.suffixOnes = right.suffixOnes;
if (right.suffixOnes == right.length) res.suffixOnes = right.length + left.suffixOnes;
res.maxOnes = left.suffixOnes + right.prefixOnes;
res.maxOnes = std::max(res.maxOnes, left.maxOnes);
res.maxOnes = std::max(res.maxOnes, right.maxOnes);
res.maxDP = std::max(left.maxDP, right.maxDP);
return res;
}
};
Node tree[4*MAXN];
void update(int l, int r, int node, int queryPos, int dpVAL)
{
if (l == r)
{
tree[node].maxDP = dpVAL;
tree[node].prefixOnes = 1;
tree[node].suffixOnes = 1;
tree[node].maxOnes = 1;
tree[node].length = 1;
return;
}
int mid = (l + r) / 2;
if (queryPos <= mid) update(l, mid, 2*node, queryPos, dpVAL);
else update(mid + 1, r, 2*node + 1, queryPos, dpVAL);
tree[node] = tree[2*node] + tree[2*node + 1];
}
Node query(int l, int r, int node, int queryL, int queryR)
{
if (queryL <= l && r <= queryR)
{
return tree[node];
}
Node res;
int mid = (l + r) / 2;
if (queryL <= mid) res = res + query(l, mid, 2*node, queryL, queryR);
if (mid + 1 <= queryR) res = res + query(mid + 1, r, 2*node + 1, queryL, queryR);
return res;
}
void update(int pos, int val)
{
update(1, n, 1, pos, val);
}
int queryOnes(int l, int r)
{
return query(1, n, 1, l, r).maxOnes;
}
int queryDP(int l, int r)
{
return query(1, n, 1, l, r).maxDP;
}
};
int a[MAXN];
int dp[MAXN];
int perm[MAXN];
SegmentTree tree;
void solve()
{
std::iota(perm + 1, perm + 1 + n, 1);
std::sort(perm + 1, perm + 1 + n, [&](int x, int y)
{
return a[x] > a[y] || (a[x] == a[y] && x < y);
});
int res = 0;
for (int i = 1 ; i <= n ; ++i)
{
int l = perm[i], r = n, mid;
while (l < r - 1)
{
mid = (l + r) / 2;
if (tree.queryOnes(perm[i] + 1, mid) < d) l = mid;
else r = mid;
}
dp[perm[i]] = tree.queryDP(perm[i] + 1, r) + 1;
tree.update(perm[i], dp[perm[i]]);
res = std::max(res, dp[perm[i]]);
}
std::cout << res << '\n';
}
void input()
{
std::cin >> n >> d;
for (int i = 1 ; i <= n ; ++i)
{
std::cin >> a[i];
}
}
void fastIOI()
{
std::ios_base :: sync_with_stdio(0);
std::cout.tie(nullptr);
std::cin.tie(nullptr);
}
int main()
{
fastIOI();
input();
solve();
return 0;
}
