#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define all(x) (x).begin(), (x).end()
using namespace std;
using ll = long long;
using vi = vector<int>;
const char el = '\n';
const int maxn = 2e5+7;
const int inf = 1e9+7;
struct Bitcoin {
vi arr;
int n;
Bitcoin (int sz) : n(sz) {
arr.assign(sz+1, 0);
}
void upd(int i, int v) {
for (; i <= n; i+= i& -i) arr[i] = max(arr[i], v);
}
int get(int i) {
int res = 0;
for (; i > 0; i-= i& -i) res = max(res, arr[i]);
return res;
}
};
int n, m, cnt=1;
int a[maxn];
vi b;
map<int, int> compress;
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
// freopen("test.inp", "r", stdin);
// freopen(".inp", "r", stdin);
// freopen(".out", "w", stdout);
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> a[i];
if (m*i - a[i] >= 0) b.pb(m*i - a[i]);
}
for (auto i : b) compress[i] = 0;
for (auto& i : compress) i.se = cnt++;
for (auto& i : b) i = compress[i];
Bitcoin dp(cnt);
for (auto i : b) {
dp.upd(i, dp.get(i) + 1);
}
cout << n - dp.get(cnt);
return 0;
}
