#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
using namespace std;
using ll = long long;
using ld = long double;
const int maxn = 3e5 + 5;
const int maxN = 1e5;
const int mod = 1e9 + 7;
const ll inf = 1e18;
const int tt = 5e3 + 5;
const int base = 31;
const int lim = 100;
const int BLOCK_SIZE = 340;
const int TWO_MOD_INV = 500000004;
int dx[] = {0,-1,0,1,-1,1,-1,1};
int dy[] = {-1,0,1,0,-1,1,1,-1};
int n,m;
int a[maxn];
int d[maxn];
void Read()
{
cin >> n >> m;
for(int i = 1;i <= n;i++)
{
cin >> a[i];
a[i] = i*m - a[i];
}
int sz = 0;
int res = 0;
for(int i = 1;i <= n;i++)
{
if(a[i] >= 0)
{
int k = upper_bound(d + 1,d + sz + 1,a[i]) - d;
sz = max(sz,k);
res = max(res,sz);
d[k] = a[i];
}
}
cout << n - res;
}
void Solve()
{
}
void Debug()
{
}
int32_t main()
{
// freopen("test.in","r",stdin);
// freopen("test.out","w",stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
int tt;
tt = 1;
// Prepare();
// cin >> tt;
for(int i = 1; i <= tt; i++)
{
Read();
Solve();
Debug();
}
}
/*
*/
