#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define int long long
#define double long double
using namespace std;
using namespace __gnu_pbds;
long dx[] = {0, 0, 1, -1, 1, 1, -1, -1};
long dy[] = {1, -1, 0, 0, 1, -1, 1, -1};
const int Mod = (int)1e9 + 7;
double logBase(int a, int b) { return (double)log2l(a) / log2l(b); }
int gcd(int a, int b)
{
return b == 0 ? a : gcd(b, a % b);
}
int lcm(int a, int b)
{
return (a / gcd(a, b)) * b;
}
// int inv(int a, int mod) { return a <= 1 ? a : mod - (int)(mod / a) * inv(mod % a, mod) % mod; }
int pmod(int x, int p, int mod)
{
int ans = 1;
int pre = x % mod;
while (p)
{
if (p % 2)
ans *= (pre) % mod;
p /= 2;
ans %= mod;
pre = (pre * pre) % mod;
}
return ans;
}
int inv(int a, int mod) { return pmod(a, mod - 2, mod); }
void fileIO()
{
#ifndef ONLINE_JUDGE
freopen("cowjog.in", "r", stdin);
freopen("cowjog.out", "w", stdout);
#endif
}
/////ost.order_of_key (k) : number of items strictly smaller than k .
//// ost.find_by_order(k) : K-th element in a set (counting from zero).
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <class T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = (2e3) + 100;
int32_t main()
{
ios::sync_with_stdio(false);
cin.tie(NULL);
// fileIO();
int Test_cases = 1;
// cin >> Test_cases;
while (Test_cases--)
{
int n, m;
cin >> n >> m;
int A[n];
for (int i = 0; i < n; i++)
{
cin >> A[i];
A[i] -= m * i;
A[i] *= -1;
}
vector<int> dp = {-m};
for (int i = 0; i < n; i++)
{
auto it = upper_bound(dp.begin(), dp.end(), A[i]) - dp.begin();
if (it == 0)
{
continue;
}
if (it == dp.size())
{
dp.push_back(A[i]);
}
else
{
dp[it] = min(dp[it], A[i]);
}
}
cout << n - dp.size() + 1 << endl;
}
return 0;
}
