#include<bits/stdc++.h>
using namespace std;
const int N = 20 + 3;
#define int long long
int mod = 998244353;
void solve(){
int n,m;cin >> n >> m;
vector<int> a(n + 1), Vec = {0};
for(int i = 1 ; i <= n ; i ++)cin >> a[i];
for(int i = 1 ; i <= n ; i ++){
int t = -a[i] + m * i;
if (t < 0) continue;
int j = upper_bound(Vec.begin(), Vec.end(), t) - Vec.begin();
if (j == Vec.size()) Vec.push_back(t);
else Vec[j] = t;
}
cout << n - Vec.size() + 1 <<'\n';
}
signed main(){
int t=1;
// cin>>t;
while(t--){
solve();
}
}
