#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];
#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 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;
		}
		//make(pl);
        //make(pr);
		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;
	}
    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;
    }
    void dfs(int p,int L=1,int R=tb){
        if(!p)return;
        if(L==R){
            printf("p=%d [%d,%d] mx=%lld %lld %lld\n",p,L,R,a[p].mx,a[p].mxl,a[p].mxr);
            return;
        }
        make(pl);make(pr);
        pushdown(p);
        int mid=(L+R)>>1;
        dfs(pl,L,mid);dfs(pr,mid+1,R);
    }
}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++){
        for(int j=0;j<=l0;j++){
            if(!rt[i][j])continue;
            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];
            int now=lower_bound(b+1,b+tb+1,pi[i]-j)-b;
            ll v1=tre.ask(rt[i][j],1,l1-1,1)+b[l1];//2 yi
            if(!rt[i+1][il])tre.make(rt[i+1][il]);
            tre.change(rt[i+1][il],now,v1);
            ll v2=tre.ask(rt[i][j],r1+1,tb,2)-b[r1],v3;
            if(!rt[i+1][ir])tre.make(rt[i+1][ir]);
            tre.change(rt[i+1][ir],now,v2);
            for(int k=l1;k<=r1;k++){
                v3=tre.ask(rt[i][j],k,k,0);
                if(v3>=inf)continue;
                if(!rt[i+1][pi[i+1]-b[k]])tre.make(rt[i+1][pi[i+1]-b[k]]);
                tre.change(rt[i+1][pi[i+1]-b[k]],now,v3);
            }
            //1 yi
            if(now<l1){
                tre.update(rt[i][j],1,tb,b[l1]-b[now]);
                tre.merge(rt[i+1][il],rt[i][j]);
            }
            else if(now>r1){
                tre.update(rt[i][j],1,tb,b[now]-b[r1]);
                tre.merge(rt[i+1][ir],rt[i][j]);
            }
            else{
                tre.merge(rt[i+1][pi[i+1]-b[now]],rt[i][j]);
            }
            if(tiao==1)puts("");
        }
    }
    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;
}