#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 IOS ios::sync_with_stdio(0); cin.tie(0);
#define lli long long int
#define pb push_back
#define all(x) x.begin(),x.end()
#define rep(i,a,b) for(int i=a;i<=b;i++)
#define repp(i,a,b) for(int i=a;i>=b;i--)
#define vi vector<lli>
#define vvi vector<vi>
#define vpi vector<pair<lli,lli>>
#define pi pair<lli,lli>
#define msi multiset<lli>
#define mspi multiset<pair<lli,lli>>
#define mii map<lli,lli>
#define mpi map<pair<lli,lli>,lli>
#define si set<lli>
#define spi set<pair<lli,lli>>
#define qi queue<lli>
#define pqi priority_queue<lli>
#define pqimin priority_queue<lli,vi,greater<lli>>
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T1, class T2> using ordered_map = tree<T1, T2, less<T1>, rb_tree_tag, tree_order_statistics_node_update>;
void solve() {
lli n,m;
cin>>n>>m;
vi a(n+1);
a[0] = 0;
rep(i,1,n){
cin>>a[i];
a[i] = m*(i) - a[i];
}
vi dp;
dp.pb(a[0]);
rep(i,1,n){
if(a[i]<0)continue;
lli indx = upper_bound(all(dp),a[i]) - dp.begin();
if(indx==dp.size()){
dp.pb(a[i]);
}
else{
dp[indx] = a[i];
}
}
// for(auto i: dp){
// cout<<i<<" ";
// }
// cout<<"\n";
lli ans = dp.size()-1;
cout<<n-ans<<"\n";
}
signed main() {
IOS int t=1;
// cin>>t;
while(t--)
solve();
return 0;
}
