#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb(x) push_back(x)
#define mp(x, y) make_pair(x, y)
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#define dbg(x...) cerr << "\e[91m"<<__func__<<":"<<__LINE__<<" [" << #x << "] = ["; _print(x); cerr << "\e[39m" << endl;
const int N=1e6+10;
//const ll mod=998244353;
const ll mod=1000000007;
const int intinf=2e9;
const ll llinf=9e18;
const ld eps=2e-7;
ll n, m;
void solve(){
cin >> n >> m;
vector<ll> a(n + 1);
a[0] = 0;
for(int i = 1; i <= n; i++)
cin >> a[i];
n++;
vector<ll> A;
for(int i = 0; i < n; i++){
a[i] = m * i - a[i];
if(a[i] >= 0)
A.pb(a[i]);
}
vector<ll> dp;
for(ll x : A){
ll pos = upper_bound(all(dp), x) - dp.begin();
if(pos == dp.size())
dp.pb(x);
else
dp[pos] = x;
}
cout << n - dp.size() << "\n";
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t=1;
//cin >> t;
while(t--)
solve();
return 0;
}
