#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define F first
#define S second
#define el '\n'
#define cout(x) for(auto v:x)cout<<v<<' ';cout<<el
#define coutp(x) for(auto v:x)cout<<v.F<<' '<<v.S<<el
#define cin(x) for(auto &v:x)cin>>v;
#define all(x) x.begin(),x.end()
#define ll long long
#define sz(x) (int)x.size()
const int N = 2e6 + 5, M = 1e2 + 5, Mod = 1e9 + 7;
int dx[8] = {1, -1, 0, 0, 1, -1, 1, -1};
int dy[8] = {0, 0, 1, -1, 1, -1, -1, 1};
void solve(int T)
{
int n, m;
cin >> n >> m;
vector<int> a, v;
for (int i = 1; i <= n; i++)
{
int x;
cin >> x;
if (i * m >= x)
a.push_back(m * i - x);
}
for (auto i : a)
{
int x = upper_bound(all(v), i) - v.begin();
if (x == v.size())
v.push_back(i);
else
v[x] = i;
}
cout << n - sz(v) << el;
}
int32_t main()
{
// #ifndef ONLINE_JUDGE
// freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
// #endif
// freopen("cowjog.in", "r", stdin);
// freopen("cowjog.out", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int tc = 1;
// cin >> tc;
for (int i = 1; i <= tc; i++)solve(i);
return 0;
}
