#include <bits/stdc++.h>
#define NN 34570
using namespace std;
ifstream fin ("euro.in");
ofstream fout ("euro.out");



long long n, t, aux, val;
long long sp[NN], dp[NN];

int main()
{
    fin >> n >> t;
    for(int i = 1 ; i <= n ; i++)
    {
        fin >> val;
        sp[i] = sp[i-1] + val;
    }
    for(int i = 1 ; i <= n ; i++)
    {
        dp[i] = sp[i] * i - t;
        for(int j = 1 ; j < i ; j++)
        {
            aux = dp[j] + (sp[i] - sp[j]) * i - t;
            dp[i] = max(aux, dp[i]);
        }
    }
    fout << dp[n];
    return 0;
}