/* Mugurel Ionut Andreica - Bucuresti, ROMANIA */

/* Time Complexity: O(N*logN*logN) */

/* Score: 100 points */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define filein "euro.in"
#define fileout "euro.out"
#define maxn 34568

typedef struct { long li,ls,fs,fd,tata,lineindex; } nod;

double s[maxn],c[maxn],max[maxn],t;
long list[maxn];
nod arb[2*maxn];
long n,narb;

void readdata(void);
void buildtree(void);
void compute(void);
void writedata(void);

int main()
{
readdata();
buildtree();
compute();
writedata();
return 0;
}

void readdata(void)
{
long i;
double e;

freopen(filein,"r",stdin);
scanf("%ld %lf",&n,&t);

s[0]=0;
for (i=1;i<=n;i++)
  {
  scanf("%lf",&e);
  s[i]=s[i-1]+e;
  }
}

void buildtree(void)
{
long i,j,k,p;

for (i=1;i<=n;i++)
  {
  arb[i].li=arb[i].ls=list[i]=i;
  arb[i].fs=arb[i].fd=arb[i].tata=0;
  }
  
k=narb=n;
while (k>1)
  {
  j=0;
  for (i=1;i<k;i++)
    if (i%2==1)
      {
      narb++;
      arb[narb].li=arb[list[i]].li;
      arb[narb].ls=arb[list[i+1]].ls;
      arb[narb].fs=list[i];
      arb[narb].fd=list[i+1];
      arb[list[i]].tata=narb;
      arb[list[i+1]].tata=narb;
      arb[narb].tata=0;
      j++;
      list[j]=narb;
      }

  if (k%2==1)
    {
    j++;
    list[j]=list[k];
    }

  k=j;
  }
}

double getmax(long i,long& lineindex)
{
long line,p;
double res;

line=-1;
p=i;
while (p>0)
  {
  if (arb[p].lineindex>line)
    line=arb[p].lineindex;

  p=arb[p].tata;
  }

res=max[line]+c[line]*(i-line);
lineindex=line;
return res;
}

long locatelow(long line)
{
long poz,li,ls,m,lm;
double vline,vm;

li=line+1; ls=n; poz=n+1;
while (li<=ls)
  {
  m=(li+ls)>>1;

  vline=max[line]+c[line]*(m-line);
  vm=getmax(m,lm);

  if (c[lm]<c[line])
    {
    if (vm<vline)
      {
      poz=m;
      ls=m-1;
      }
    else
      li=m+1;
    }
  else
    ls=m-1;
  }

return poz;
}

long locatehigh(long line)
{
long poz,li,ls,m,lm;
double vline,vm;

vm=getmax(n,lm);
vline=max[line]+c[line]*(n-line);
if (c[line]>c[lm] && vline>vm)
  return n;

li=line+1; ls=n; poz=line;
while (li<=ls)
  {
  m=(li+ls)>>1;

  vline=max[line]+c[line]*(long long)((m-line));
  vm=getmax(m,lm);

  if (c[lm]>c[line])
    {
    if (vm<vline)
      {
      poz=m;
      li=m+1;
      }
    else
      ls=m-1;
    }
  else
    li=m+1;
  }

return poz;
}

void setmax(long li,long ls,long num,long x)
{
long fs,fd;

fs=arb[num].fs;
fd=arb[num].fd;

if (li==arb[num].li && ls==arb[num].ls)
  arb[num].lineindex=x;
else
if (li==arb[num].li)
  {
  if (arb[fd].li<=ls)
    {
    setmax(li,arb[fs].ls,fs,x);
    setmax(arb[fd].li,ls,fd,x);
    }
  else
    setmax(li,ls,fs,x);
  }
else
if (ls==arb[num].ls)
  {
  if (arb[fs].ls>=li)
    {
    setmax(li,arb[fs].ls,fs,x);
    setmax(arb[fd].li,ls,fd,x);
    }
  else
    setmax(li,ls,fd,x);
  }
else
  {
  if (ls<=arb[fs].ls)
    setmax(li,ls,fs,x);
  else
  if (li>=arb[fd].li)
    setmax(li,ls,fd,x);
  else
    {
    setmax(li,arb[fs].ls,fs,x);
    setmax(arb[fd].li,ls,fd,x);
    }
  }
}

void compute(void)
{
long i,j,p1,p2;

/* compute the C array */
for (i=0;i<=n;i++)
  c[i]=s[n]-s[i];

/* init the tree */
for (i=1;i<=narb;i++)
  arb[i].lineindex=0;
max[0]=0;

/* do the smart things */
for (i=1;i<n;i++)
  {
  max[i]=getmax(i,j)-t;

  p1=locatelow(i);
  p2=locatehigh(i);

  if (p1<=p2)
    setmax(p1,p2,narb,i);
  }
}

void writedata(void)
{
long nouse;

freopen(fileout,"w",stdout);
printf("%.0lf\n",getmax(n,nouse)-t);
}