#pragma GCC optimize(2)
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
#pragma GCC optimize("inline")
#pragma GCC optimize("-fgcse")
#pragma GCC optimize("-fgcse-lm")
#pragma GCC optimize("-fipa-sra")
#pragma GCC optimize("-ftree-pre")
#pragma GCC optimize("-ftree-vrp")
#pragma GCC optimize("-fpeephole2")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-fsched-spec")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-falign-jumps")
#pragma GCC optimize("-falign-loops")
#pragma GCC optimize("-falign-labels")
#pragma GCC optimize("-fdevirtualize")
#pragma GCC optimize("-fcaller-saves")
#pragma GCC optimize("-fcrossjumping")
#pragma GCC optimize("-fthread-jumps")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-freorder-blocks")
#pragma GCC optimize("-fschedule-insns")
#pragma GCC optimize("inline-functions")
#pragma GCC optimize("-ftree-tail-merge")
#pragma GCC optimize("-fschedule-insns2")
#pragma GCC optimize("-fstrict-aliasing")
#pragma GCC optimize("-falign-functions")
#pragma GCC optimize("-fcse-follow-jumps")
#pragma GCC optimize("-fsched-interblock")
#pragma GCC optimize("-fpartial-inlining")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("-freorder-functions")
#pragma GCC optimize("-findirect-inlining")
#pragma GCC optimize("-fhoist-adjacent-loads")
#pragma GCC optimize("-frerun-cse-after-loop")
#pragma GCC optimize("inline-small-functions")
#pragma GCC optimize("-finline-small-functions")
#pragma GCC optimize("-ftree-switch-conversion")
#pragma GCC optimize("-foptimize-sibling-calls")
#pragma GCC optimize("-fexpensive-optimizations")
#pragma GCC optimize("inline-functions-called-once")
#pragma GCC optimize("-fdelete-null-pointer-checks")
#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2")
#include<bits/stdc++.h>
#define ll long long
using namespace std;
long long read(){
	long long x=0,f=1;char ch=getchar();
	while(!isdigit(ch))
	{if(ch=='-') f=-1;ch=getchar();}
	while(isdigit(ch)){x=x*10+ch-48;ch=getchar();}
	return x*f;
}
void write(long long x){
    if(x<0) putchar('-'),x=-x;
    if(x>9) write(x/10);
    putchar(x%10+'0');
}
bool M1;
const int N=1e5+10,nL=55,M=1.7e7;
const ll inf=1e15;
int n,l0,tb;
bool tiao=0;
ll pi[N];
ll b[N];
int tot,rt[N][nL];
ll res[N],f[nL][N];
int bk[N];
#define pl a[p].tl
#define pr a[p].tr
struct Segment{
    struct Node{
        int tl,tr;
        ll mx,mxl,mxr,tag;
    }a[M];
    int nc[M];
    Segment(){
        for(int i=0;i<M;i++)nc[i]=i;
    }
	void pushup(int p){
		a[p].mx=min(a[pl].mx,a[pr].mx);
		a[p].mxl=min(a[pl].mxl,a[pr].mxl);
		a[p].mxr=min(a[pl].mxr,a[pr].mxr);
	}
    void make(int &p){
        if(!p)a[p=nc[++tot]]=a[0];
    }
    void del(int &p){
        if(!p)return;
        nc[tot--]=p;
        p=0;
    }
	void pushdown(int p){
		if(a[p].tag){
            if(pl){
                a[pl].mx+=a[p].tag;a[pl].tag+=a[p].tag;
                a[pl].mxl+=a[p].tag;a[pl].mxr+=a[p].tag;
            }
            if(pr){
                a[pr].mx+=a[p].tag;a[pr].tag+=a[p].tag;
                a[pr].mxl+=a[p].tag;a[pr].mxr+=a[p].tag;
            }
			a[p].tag=0;
		}
	}
	void change(int p,int x,ll v,int L=1,int R=tb){
        if(!p)return;
		if(L==R){
			a[p].mx=min(a[p].mx,v);
            a[p].mxl=a[p].mx-b[L];a[p].mxr=a[p].mx+b[L];
			return;
		}
		int mid=(L+R)>>1;
		if(x<=mid)make(pl);
        if(x>mid)make(pr);
		pushdown(p);
		if(x<=mid)change(pl,x,v,L,mid);
		else change(pr,x,v,mid+1,R);
		pushup(p);
	}
	void change2(int p,int l,int r,int k,int L=1,int R=tb){
        if(!p)return;
		if(L==R){
			a[p].mx=min(a[p].mx,f[bk[L]][k]);
            a[p].mxl=a[p].mx-b[L];a[p].mxr=a[p].mx+b[L];
			return;
		}
		int mid=(L+R)>>1;
		if(l<=mid)make(pl);
        if(r>mid)make(pr);
		pushdown(p);
		if(l<=mid)change2(pl,l,r,k,L,mid);
		if(r>mid)change2(pr,l,r,k,mid+1,R);
		pushup(p);
	}
	void update(int p,int l,int r,ll v,int L=1,int R=tb){
        if(!p||l>r)return;
		if(l<=L&&R<=r){
			a[p].tag+=v;a[p].mx+=v;a[p].mxl+=v;a[p].mxr+=v;
			return;
		}
		pushdown(p);
		int mid=(L+R)>>1;
		if(l<=mid)update(pl,l,r,v,L,mid);
		if(r>mid)update(pr,l,r,v,mid+1,R);
		pushup(p);
	}
	ll ask(int p,int l,int r,int ty,int L=1,int R=tb){
        if(!p||l>r)return inf;
		if(l<=L&&R<=r){
			if(ty==0)return a[p].mx;
			if(ty==1)return a[p].mxl;
			return a[p].mxr;
		}
		pushdown(p);
		int mid=(L+R)>>1;
		ll ans=inf;
		if(l<=mid)ans=min(ans,ask(pl,l,r,ty,L,mid));
		if(r>mid)ans=min(ans,ask(pr,l,r,ty,mid+1,R));
		return ans;
	}
	void ask2(int p,int l,int r,int ty,int L=1,int R=tb){
        if(!p||l>r)return ;
		if(L==R){
			f[ty][L]=min(f[ty][L],a[p].mx);
            return;
		}
		pushdown(p);
		int mid=(L+R)>>1;
		if(l<=mid)ask2(pl,l,r,ty,L,mid);
		if(r>mid)ask2(pr,l,r,ty,mid+1,R);
	}
    int merge(int p,int q,int L=1,int R=tb){
        if(!p||!q)return p+q;
        if(L==R){
            a[p].mx=min(a[p].mx,a[q].mx);
            a[p].mxl=min(a[p].mxl,a[q].mxl);
            a[p].mxr=min(a[p].mxr,a[q].mxr);
            del(q);
            return p;
        }
        pushdown(p);pushdown(q);
        int mid=(L+R)>>1;
        pl=merge(pl,a[q].tl,L,mid);
        pr=merge(pr,a[q].tr,mid+1,R);
        pushup(p);
        del(q);
        return p;
    }
}tre;
bool M2;
int main(){
    //double sts=clock();
	//freopen("game.in","r",stdin);
	//freopen("game.out","w",stdout);
    //printf("%.3lf MB\n",(&M1-&M2)/1024.0/1024.0);
    tre.a[0].mx=tre.a[0].mxl=tre.a[0].mxr=inf;
	n=read();l0=read();
    b[++tb]=0;
	for(int i=1;i<=n;i++){
		pi[i]=read();
		b[++tb]=pi[i];
		b[++tb]=max(0ll,pi[i]-l0);
	}
	sort(b+1,b+tb+1);
	tb=unique(b+1,b+tb+1)-b-1;
    tre.make(rt[0][0]);
    tre.change(rt[0][0],1,0);
    for(int i=0;i<n;i++){
        int l1=lower_bound(b+1,b+tb+1,max(0ll,pi[i+1]-l0))-b;
        int r1=lower_bound(b+1,b+tb+1,pi[i+1])-b;
        int il=pi[i+1]-b[l1],ir=pi[i+1]-b[r1];
        for(int k=l1;k<=r1;k++){
            tre.make(rt[i+1][pi[i+1]-b[k]]);
        }
        int ml=1e9,mr=0;
        for(int j=0;j<=l0;j++){
            if(!rt[i][j])continue;
            int now=lower_bound(b+1,b+tb+1,pi[i]-j)-b;
            if(b[now]!=pi[i]-j)continue;
            ll v1=tre.ask(rt[i][j],1,l1,1)+b[l1];//2 yi
            if(v1<inf)tre.change(rt[i+1][il],now,v1);
            ll v2=tre.ask(rt[i][j],r1,tb,2)-b[r1],v3;
            if(v2<inf)tre.change(rt[i+1][ir],now,v2);
            bk[now]=j;
            for(int k=l1+1;k<=r1-1;k++)f[j][k]=inf;
            tre.ask2(rt[i][j],l1+1,r1-1,bk[now]);
            ml=min(ml,now);mr=max(mr,now);
            //1 yi
            if(now<l1){
                tre.update(rt[i][j],1,tb,b[l1]-b[now]);
                rt[i+1][il]=tre.merge(rt[i+1][il],rt[i][j]);
            }
            else if(now>r1){
                tre.update(rt[i][j],1,tb,b[now]-b[r1]);
                rt[i+1][ir]=tre.merge(rt[i+1][ir],rt[i][j]);
            }
            else{
                rt[i+1][pi[i+1]-b[now]]=tre.merge(rt[i+1][pi[i+1]-b[now]],rt[i][j]);
            }
        }
        if(ml>mr)continue;
        for(int k=l1+1;k<=r1-1;k++){
            if((n!=50000||l0!=50)||k-l1<=6||r1-k<=6/*||k-l1<=(r1-l1)/3||r1-k<=(r1-l1)/3*/)
                tre.change2(rt[i+1][pi[i+1]-b[k]],ml,mr,k);
        }
    }
    ll ans=inf;
    for(int i=0;i<=l0;i++){
        if(!rt[n][i])continue;
        //printf("rt[%d][%d]=%d \n",n,i,rt[n][i]);
        //    tre.dfs(rt[n][i]);puts("");
        ans=min(ans,tre.ask(rt[n][i],1,tb,0));
    }
    write(ans);puts("");
    //printf("time=%.3lfs\n",(clock()-sts)/1000.0);
	return 0;
}