//#pragma GCC optimize("O3,unroll-loops,Ofast")
//#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
using namespace std;
// using namespace __gnu_pbds;
#define MAX 10005
#define pb push_back
// #define mp make_pair
#define int long long
#define f first
#define s second
#define vi vector<int>
#define pii pair<int,int>
#define si set<int>
#define vpii vector<pair<int,int>>
const int mod = 1e9+7;
const int INF = 1e18;
// myMap.begin()->first : key
// myMap.begin()->second : value
int epow(int a,int b){int ans=1;while(b){if(b&1) ans*=a;a*=a;b>>=1;ans%=mod;a%=mod;}return ans%mod;}
int gcd(int a,int b) {if(a<b)swap(a,b);while(b){int tmp=b;b=a%b;a=tmp;}return a;}
int mul(int a,int b){return ((a%mod)*(b%mod))%mod;}
int sum(int a,int b){return ((a%mod)+(b%mod))%mod;}
//typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>ordered_set;
// typedef
// tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update>ordered_multiset;
void solve(){
int n,m; cin>>n>>m;
vi arr(n+5);
for(int i=1;i<=n;i++) cin>>arr[i],arr[i]-=i*m;
multiset<int> lis;
for(int i=1;i<=n;i++){
if(arr[i]>=0) continue;
auto itr = upper_bound(lis.begin(),lis.end(),arr[i]);
if(lis.empty() || itr==lis.begin()) lis.insert(arr[i]);
else{
itr--; if(*itr==arr[i]) lis.insert(arr[i]);
lis.erase(lis.find(*itr)); lis.insert(arr[i]);
}
}
// for(auto u : lis) cout<<u<<" ";
cout<<n-(int)lis.size()<<endl;
}
int32_t main(/*int32_t argc, char* argv[]*/){
std::ios_base::sync_with_stdio(0); std::cin.tie(0);
// freopen("cowjog.in", "r", stdin);
// freopen("cowjog.out", "w", stdout);
int t=1;
// cin >> t;
while (t--) solve();
return 0;
}
