#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <class T> using oset=tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//#define int long long
#define ll long long
#define ld long double
#define ar array
#define vt vector
#define pb push_back
#define pf push_front
#define all(v) v.begin(), v.end()
#define lla(v) v.rbegin(), v.rend()
//const ll MOD=1e9+7;
const ll M=(1ll<<61)-1;
const ll MOD=998244353;
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
const ll base=uniform_int_distribution<ll>(0, M-1)(rng);
ll bpow(ll a, ll b, ll DOMDOM) {
a%=DOMDOM;
ll res=1;
while(b>0) {
if(b&1)
res=res*a%DOMDOM;
a=a*a%DOMDOM;
b>>=1;
}
return res;
}
ll floor_div(ll x, ll y) {
assert(y!=0);
if (y<0) {
y=-y;
x=-x;
}
if (x>=0) return x/y;
return (x+1)/y-1;
}
ll ceil_div(ll x, ll y) {
assert(y!=0);
if (y<0) {
y=-y;
x=-x;
}
if (x<=0) {
return x/y;
}
return (x-1)/y+1;
}
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
void tmw() {
//solve here
int n, m;
cin >> n >> m;
int a[n+1];
for(int i=1; i<=n; ++i) {
cin >> a[i];
}
vt<int> concac;
for(int i=1; i<=n; ++i) {
if(i*m>=a[i]) {
concac.pb(i*m-a[i]);
}
}
vt<int> dp;
for(auto& ele: concac) {
int pos=upper_bound(all(dp), ele)-dp.begin();
if(pos==dp.size()) {
dp.pb(ele);
}
else {
dp[pos]=ele;
}
}
cout << n-dp.size() << "\n";
}
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);
//freopen("template.inp", "r", stdin);
//freopen("template.out", "w", stdout);
int TC=1;
//cin >> TC;
while(TC--) {
tmw();
}
}
