// #include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <map>
#include <unordered_map>
#include <vector>
#include <iomanip>
#include <string>
#include <queue>
#include <set>
#include <deque>
using namespace std;
#define int long long
#define endl "\n"
#define fi first
#define se second
const int M=1203465797;
const int inf = 1e14;
const int LOG=18;
const int N=5e3+5;
int n , m , c , w , k , t=1 , q=1 , x , y , z , l , r;
int dp[N][N];
void solve(){
cin >> n >> m;
vector<int>a(n+1);
for (int i=1;i<=n;i++){
cin >> a[i];
}
for (int i=1;i<=n;i++){
for (int j=0;j<=n;j++){
dp[i][j]=n;
}
}
for (int i=1;i<=n;i++){
for (int j=1;j<=i;j++){
dp[i][j]=min(dp[i][j],j+dp[i-j][0]);
}
for (int j=0;j<i;j++){
if (a[i-1-j]+m*(j+1)>=a[i]){
dp[i][0]=min(dp[i][0],dp[i-1][j]);
}
}
}
// cout << dp[1][0] << endl;
int c=n;
for (int j=0;j<=n;j++){
c=min(c,dp[n][j]);
}
cout << c << endl;
}
signed main()
{
ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
cin.tie(0), cout.tie(0);//DO NOT USE IN INTERACTIVE
cout << fixed << setprecision(9);
srand(time(0));
// int t=1;
// cin >> t;
for (int _=1;_<=t;_++){
solve();
q++;
}
}
