#include <bits/stdc++.h>
#define fu(i, a, b) for(int i = (a); i <= (b); i++)
#define fd(i, a, b) for(int i = (a); i >= (b); i--)
#define ll long long
using namespace std;
const int N = 5e3 + 5;
const int MAXA = 5005;
const int INF = 1e9 + 5;
int n;
int lim;
int a[N];
struct Segment
{
vector<int> nodes;
void init(int n)
{
nodes.resize(4 * n + 5, INF);
}
void update(int id, int l, int r, int u, int v, int val)
{
if(v < l || u > r) return;
if(l == r) {
nodes[id] = val;
return;
}
int mid = (l + r) / 2;
update(id * 2, l, mid, u, v, val);
update(id * 2 + 1, mid + 1, r, u, v, val);
nodes[id] = min(nodes[id * 2], nodes[id * 2 + 1]);
}
int get(int id, int l, int r, int u, int v)
{
if(v < l || u > r) return INF;
if(u <= l && r <= v) return nodes[id];
int mid = (l + r) / 2;
return min(get(id * 2, l, mid, u, v), get(id * 2 + 1, mid + 1, r, u, v));
}
};
Segment f;
ll dp[MAXA + 5];
void solve()
{
f.init(MAXA);
f.update(1, 1, n, 1, 1, 0);
fu(i, 1, n)
{
fu(j, 1, MAXA)
{
int val = f.get(1, 1, MAXA, max(1, j - lim), MAXA);
dp[j] = val + (j != a[i]);
}
fu(j, 1, MAXA) {
f.update(1, 1, MAXA, j, j, dp[j]);
}
}
cout << f.get(1, 1, MAXA, 1, MAXA);
}
void read()
{
cin >> n >> lim;
fu(i, 1, n) cin >> a[i], a[i]++;
solve();
}
int main()
{
// freopen("tester.inp","r",stdin);
// freopen("tester.out","w",stdout);
ios_base::sync_with_stdio(false);cin.tie(0);
read();
}
