#include "bits/stdc++.h"
using namespace std;
#define ar array
typedef long long ll;
#define int ll
const int N = 2e5 + 5;
int a[N], dp[N];
struct ST{
int tree[N << 2];
ST(){
memset(tree, 200, sizeof tree);
}
void set(int i, int v, int lx = 0, int rx = N, int x = 1){
if(lx == rx) { tree[x] = max(tree[x], v); return; }
int m = (lx + rx) >> 1;
if(i <= m) set(i, v, lx, m, x << 1);
else set(i, v, m + 1, rx, x << 1 | 1);
tree[x] = max(tree[x << 1], tree[x << 1 | 1]);
}
int get(int l, int r, int lx = 0, int rx = N, int x = 1){
if(lx > r || rx < l) return -N;
if(lx >= l && rx <= r) return tree[x];
int m = (lx + rx) >> 1;
return max(get(l, r, lx, m, x << 1), get(l, r, m + 1, rx, x << 1 | 1));
}
}tree;
signed main(){
ios::sync_with_stdio(0); cin.tie(0);
int n, m; cin >> n >> m;
vector<int> t;
t.push_back(0);
for(int i=1;i<=n;i++){
cin >> a[i];
a[i] -= i * m;
t.push_back(a[i]);
}
sort(t.begin(), t.end());
t.erase(unique(t.begin(), t.end()), t.end());
{
int j = lower_bound(t.begin(), t.end(), a[0]) - t.begin();
tree.set(j, 0);
}
for(int i=1;i<=n;i++){
int j = lower_bound(t.begin(), t.end(), a[i]) - t.begin();
dp[i] = tree.get(j, n) + 1;
tree.set(j, dp[i]);
}
cout<<n - tree.get(0, n)<<"\n";
}
