//Solutia triviala
#include <bits/stdc++.h>
#define maxN 34570
using namespace std;
const int INF=(1<<30);
int v[maxN],dp[maxN];
int n,i,j,t,sum,sp[maxN];
int main()
{
    freopen("euro.in","r",stdin);
    freopen("euro.out","w",stdout);
    scanf("%d %d",&n,&t);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&v[i]);
        sp[i]=sp[i-1]+v[i];
        dp[i]=-INF;
        for(j=i-1;j>=0;j--)
            dp[i]=max(dp[i],dp[j]+(sp[i]-sp[j])*i);
        dp[i]=dp[i]-t;
    }
    printf("%d",dp[n]);
    return 0;
}