#include <stdio.h>
#include<iostream>
#define NMax 34600
#define in "euro.in"
#define out "euro.out" 
int n,t,L;
long long S[NMax],D[NMax],Sum,v[NMax],P[NMax];
using namespace std;
long long max(long long x,long long y)
{
	if(x>y)
		return x;
	return y;
}

int main()
{
	int i,j;
	freopen(in,"r",stdin);
	scanf("%d%d",&n,&t);
	Sum=0;
	for (i=1,L=1;i<=n;++i)
	{
		scanf("%lld",v+i);
		cout<<v[i];
		S[i]=S[i-1]+v[i];
		if (Sum<0) 
		{
			++L;
			Sum=0;
		}
		Sum+=v[i];
		P[L]=i;
	}
	fclose(stdout);
	for (i=1;i<=L;++i)
	{
		D[i]= -(1LL<<62);
		for (j=0;j<=i&&j*j<4*t; ++j)
			D[i]=max(D[i],  P[i]*(S[P[i]]-S[P[i-j]]) - t + D[i-j] ); 
	}
	
	freopen(out,"w",stdout);
	printf("%lld\n",D[L]);
	fclose(stdout);
	
	return 0;
}