#include <bits/stdc++.h>
#define inf INT_MAX
#define longlonginf LONG_LONG_MAX
#define mod 1000000007
#define MAXN 100005
#define ll long long
#define deb(x) cerr<<"[ "<<#x<<" = "<<x<<" ]";
#define yes() cout<<"YES\n";
#define no() cout<<"NO\n";
using namespace std;
ll n,m,k,q,x;
ll h;
ll ans = 0;
string subtask;
void solve(){
cin>>n>>m;
ll a[n+1];
for(int i = 1 ; i <= n ; i++){
cin>>a[i];
a[i] = i*m - a[i];
}
vector<ll>::iterator it;
vector<ll> v;
for(int i = 1 ; i <= n ; i++){
if( a[i] < 0 ) continue;
it = upper_bound(v.begin(),v.end(),a[i]);
if( it == v.end() ) v.push_back(a[i]);
else *it = a[i];
}
cout<<n-v.size()<<"\n";
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int T = 1;
//cin>>T;
for(int i = 0 ; i < T ; i++){
//cout<<"Case #"<<i+1<<": ";
solve();
}
return 0;
}
/*
not i but x
logical operator
wrong example/proof
thoroughly
wrong variables
thinking it wrong
bruh just try some test case
capitals ;-;
wrong data structure lol
count memory usement
corner case
oversized array
orders
statements
size initializer
while con
map -> array
wrong digits??
swapped variables??
check if theres any variabled
that got declared twice
find some pattern
name collision
constraints??!
mod !!
resets
*/
