#include<bits/stdc++.h>
#define int long long
#define ls tr[u].l
#define rs tr[u].r
using namespace std;
const int N=5e4+10;
int a[N];
vector<int> nums;
int b[N];
int n,m;
int root[N],idx;

int lowbit(int x){return x&-x;}

struct Tree
{
	int l,r;
	int sum,sz;
}tr[N*30];
vector<int> rt;

void insert(int &u,int l,int r,int p,int w,int c)
{
	if(!u) u=++idx;
	tr[u].sum+=w,tr[u].sz+=c;
	if(l==r) return;
	int mid=l+r>>1;
	if(p<=mid) insert(ls,l,mid,p,w,c);
	else insert(rs,mid+1,r,p,w,c);
}

inline void Ls(){for(auto &u:rt) u=ls;}

inline void Rs(){for(auto &u:rt) u=rs;}

int query(int l,int r,int k)//要求权值和<=k 
{
	int sum=0,cnt=0;
	for(auto u:rt) sum+=tr[u].sum,cnt+=tr[u].sz;
	if(l==r) return min(cnt,k/nums[l]);
	sum=0,cnt=0;
	for(auto u:rt) sum+=tr[ls].sum,cnt+=tr[ls].sz;
	int mid=l+r>>1;
	if(k>=sum) return Rs(),cnt+query(mid+1,r,k-sum);
	else return Ls(),query(l,mid,k);
}

void Insert(int x,int p,int w,int c){for(int i=x;i;i-=lowbit(i)) insert(root[i],0,nums.size()-1,p,w,c);}

int Ask(int p,int w)//编号 >=p，权值和 <=w ,最多能选几个 
{
	rt.clear();
	for(int i=p;i<=n;i+=lowbit(i)) rt.push_back(root[i]);
	return query(0,nums.size()-1,w);
}

signed main()
{
	ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	
	cin>>n>>m;
	for(int i=1;i<=n;i++) cin>>a[i],nums.push_back(a[i]);
	
	sort(nums.begin(),nums.end());
	nums.erase(unique(nums.begin(),nums.end()),nums.end());
	
	for(int i=1;i<=n;i++) b[i]=lower_bound(nums.begin(),nums.end(),a[i])-nums.begin();
	
	for(int i=1;i<=n;i++) Insert(i,b[i],a[i],1);
	
	int rem=n,cnt=0;
	while(rem)
	{
		int k=Ask(1,m),w=m;
		for(int i=1;i<=k;i++)
		{
			int l=1,r=n,ans=-1;
			while(l<=r)
			{
				int mid=l+r>>1;
				if(Ask(mid,w)>=k-i+1) ans=mid,l=mid+1;
				else r=mid-1;
			}
			Insert(ans,b[ans],-a[ans],-1);
			w-=a[ans];
		}
		cnt++;
		rem-=k;
	}
	
	cout<<cnt<<"\n";
	
	return 0;
}