#include <iostream>
#include <queue>
#include <stack>
#include <algorithm>
#include <string.h>
#include <functional>
#define task "tam"
#define size() size() * 1ll
#define all(x) (x).begin(), (x).end()
#define allr(x, sz) (x) + 1, (x) + 1 + sz
#define pb push_back
#define pii pair<int, int>
#define fi first
#define se second
#define MASK(x) (1LL << (x))
#define BIT(x,i) (((x) >> (i)) & 1)
#define numbit(x) __builtin_popcountll(x)
using namespace std;
const int N = 1e6 + 1;
const int M = 1e3 + 1;
const long long mod = 1e9 + 7;
const long long oo = 1e18 + 7;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef long long ll;
template<class t>
bool mini(t &x,t y) {
if (y < x) {
x = y;
return 1;
}
return 0;
}
template<class t>
bool maxi(t &x,t y) {
if (x < y) {
x = y;
return 1;
}
return 0;
}
void file() {
ios_base::sync_with_stdio(0);
cin.tie(0);
// freopen(task".inp", "r", stdin);
// freopen(task".out", "w", stdout);
return ;
}
int n, m;
int a[N];
void solve(int test = -1) {
cin >> n >> m;
for (int i = 1; i <= n; i++) cin >> a[i];
vi b;
for (int i = 1; i <= n; i++) if (a[i] <= i * m) {
int v = m * i - a[i];
auto z = upper_bound(all(b), v);
if (z == b.end()) b.pb(v); else {
mini(b[z - b.begin()], v);
}
}
cout << n - b.size();
}
int32_t main() {
file();
int T = 1;
// cin >> T;
for (int i = 1; i <= T; i++) {
solve(i);
}
return 0;
}
/*
*/
