#include<bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//using namespace __gnu_pbds;
using namespace std;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int>vi;
typedef vector<vector<int>>vvi;
typedef vector<ll>vl;
typedef vector<vl> vvl;
typedef pair<int,int>pi;
typedef pair<ll,ll> pl;
typedef vector<pl> vpl;
typedef vector<ld> vld;
typedef pair<ld,ld> pld;
//typedef tree<ll, null_type, less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
template<typename T> ostream& operator<<(ostream& os, vector<T>& a){os<<"[";for(int i=0; i<ll(a.size()); i++){os << a[i] << ((i!=ll(a.size()-1)?" ":""));}os << "]\n"; return os;}
#define all(x) x.begin(),x.end()
#define YES out("YES")
#define NO out("NO")
#define out(x){cout << x << "\n"; return;}
#define GLHF ios_base::sync_with_stdio(false); cin.tie(NULL)
#define print(x){for(auto ait:x) cout << ait << " "; cout << "\n";}
#define gcd __gcd
#define popcount __builtin_popcountll
#define mp make_pair
template<typename T1, typename T2> istream& operator>>(istream& is, pair<T1, T2>& p){is >> p.first >> p.second;return is;}
template<typename T1, typename T2> ostream& operator<<(ostream& os, pair<T1, T2>& p){os <<"" << p.first << " " << p.second << ""; return os;}
void usaco(string taskname){
string fin = taskname + ".in";
string fout = taskname + ".out";
const char* FIN = fin.c_str();
const char* FOUT = fout.c_str();
freopen(FIN, "r", stdin);
freopen(FOUT, "w", stdout);
}
template<typename T>
void read(vector<T>& v){
int n=v.size();
for(int i=0; i<n; i++)
cin >> v[i];
}
template<typename T>
vector<T>UNQ(vector<T>a){
vector<T>ans;
for(T t:a)
if(ans.empty() || t!=ans.back())
ans.push_back(t);
return ans;
}
ll ceil(ll a,ll b){
ll ans=a/b;
if(a%b)ans++;
return ans;
}
ld log (ld a,ld b){return log(b)/log(a);}
ll power(ll base, ll exp,ll M=1e9+7){//(base^exp)%M
ll ans=1;
while(exp){
if(exp%2==1)ans=((ans%M)*(base%M))%M;
base=((base%M)*(base%M))%M;
exp/=2;
}
return ans;
}
string to_base(int n,int new_base){
string s;
int nn=n;
while(nn){
s+=to_string(nn%new_base);
nn/=new_base;
}
reverse(all(s));
return s;
}
ll lcm(ll a,ll b){
ll x= (a/gcd(a,b));
return b*x;
}
vl generate_array(ll n,ll mn=1,ll mx=1e18+1,bool permuatation=0){
if(permuatation){
vl a(n);
for(int i=0; i<n; i++)
a[i]=i+1;
random_shuffle(all(a));
return a;
}
if(mx==1e18+1)
mx=n;
vl ans(n);
for(int i=0; i<n;i++)
ans[i]=(mn+rand()%(mx-mn+1));
return ans;
}
string substr(string s,int l,int r){
string ans;
for(int i=l; i<=r; i++)
ans+=s[i];
return ans;
}
vl _fact;
ll _inverse(ll n,ll m=1e9+7){
if(gcd(n,m)!=1)return -1;
else return power(n,m-2,m);
}
ll choose(ll n,ll k,ll m=1e9+7){
if(_fact.empty()) {
vl fact(n + 1);
fact[0] = 1;
for (int i = 1; i <= n; i++)
fact[i] = (fact[i - 1] * i) % m;
_fact=fact;
}
return (_fact[n]*_inverse(_fact[k]*_fact[n-k],m))%m;
}
vl SIEVE(int n){
vector<bool>ans(n+1);
vl p;
for(int i=2; i<=n; i++)
ans[i]=1;
for(int i=2; i*i<=n; i++) {
if (ans[i]) {
for (int j = i * i; j <= n; j += i)
ans[j] = 0;
}
}
for(int i=1; i<=n; i++)
if(ans[i])p.push_back(i);
return p;
}
void solve();
int main(){
GLHF;
int t=1;
//cin >> t;
while(t--)
solve();
}
ll lis(vl a){
ll ans=1;
ll n=a.size();
vl dp(n+1,1e18);
for(int i=0; i<n; i++){
if(a[i]<0)continue;
ll j=-1,l=1,r=i+1;
while(l<=r){
ll m=r-(r-l)/2;
if(a[i]<dp[m]){
j=m;
r=m-1;
}
else
l=m+1;
}
ans=max(ans,j);
dp[j]=a[i];
}
return ans;
}
void solve() {
ll n,m;
cin >> n >> m;
vl a(n+1);
for(int i=1; i<=n; i++)
cin >> a[i];
for(int i=0; i<=n; i++)
a[i]=-(a[i]-i*m);
out(a.size()-lis(a))
}
