#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define fast ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
const ll inf = 1e9 + 7;
const ll mod = 1e9 + 7;
const ll start = 1e6 + 7;
const ll maxi = 1e5;
const int N = 1e6 + 5;
ll n, m, say, ans;
void solve() {
cin>>n>>m;
vector<ll>v(n), a;
for(int i=0; i<n; i++)
cin>>v[i];
for(int i=0; i<n; i++) {
ans=m*(i+1)-v[i];
if(ans>=0) {
auto it = upper_bound(a.begin(), a.end(), ans);
if(it==a.end())
a.push_back(ans);
else
a[it-a.begin()]=ans;
}
}
cout<<n-a.size()<<'\n';
}
signed main()
{
fast;
ll T = 1;
//cin >> T;
while(T--) {
solve();
}
return 0;
}
