#include <bits/stdc++.h>
#define FOR(i, l, r, x) for(int i = l; i <= r; i += x)
#define FOD(i, l, r, x) for(int i = l; i >= r; i -= x)
#define debug(x) cout << "[DEBUG]: " << #x << " = " << x << endl;
#define int long long
using namespace std;
const int N = 2e5 + 5;
const int mod = 1e9 + 7;
const int INF = 1e18;
int n, m, H[N];
namespace sub2 {
int dp[5005][5005], suffix[5005];
void solve() {
int maxi = *max_element(H + 1, H + n + 1);
memset(dp, 0x3f, sizeof(dp));
memset(suffix, 0x3f, sizeof(suffix));
dp[1][0] = 0;
suffix[maxi] = dp[1][maxi];
FOD(cur_h, maxi - 1, 0, 1) {
suffix[cur_h] = min(suffix[cur_h + 1], dp[1][cur_h]);
}
FOR(i, 2, n, 1) {
FOR(cur_h, 0, maxi, 1) {
int changed = (cur_h != H[i]);
dp[i][cur_h] = min(dp[i][cur_h], suffix[max(cur_h - m, 0LL)] + changed);
}
suffix[maxi] = dp[i][maxi];
FOD(cur_h, maxi - 1, 0, 1) {
suffix[cur_h] = min(suffix[cur_h + 1], dp[i][cur_h]);
}
}
int res = INF;
FOR(cur_h, 0, maxi, 1) {
res = min(res, dp[n][cur_h]);
}
cout << res << '\n';
}
}
void solve() {
cin >> n >> m;
++n;
FOR(i, 2, n, 1) cin >> H[i];
if (n <= 5000 && *max_element(H + 1, H + n + 1) <= 5000) {
sub2::solve();
}
}
signed main() {
#define name "task"
if (ifstream(name".inp")) {
freopen(name".inp", "r", stdin);
freopen(name".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
solve();
}
