#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define ff first
#define ss second
#define pb push_back
template<class T, class U> inline bool chmin(T& a, const U& b) { if (a > b) { a = b; return true; } return false; }
template<class T, class U> inline bool chmax(T& a, const U& b) { if (a < b) { a = b; return true; } return false; }
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//#define rnd(l, r) uniform_int_distribution <int> (l, r)(rng)
const int inf = 1e9;
void solve(){
int n, m;
cin >> n >> m;
vector<int> a(n);
int x = m;
for(int &i:a){
cin >> i;
i = x - i;
x += m;
}
vector<int> dp;
for(int i = 0; i < n; i++){
int ps = upper_bound(all(dp), a[i]) - dp.begin();
if(ps == dp.size())dp.pb(a[i]);
else dp[ps] = a[i];
}
cout << n - dp.size() << '\n';
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);cout.tie(nullptr);
int tt = 1;
//cin >> tt;
while(tt--){
solve();
};
}
