#include <bits/stdc++.h>
using namespace std;
ifstream in("euro.in");
ofstream out("euro.out");
typedef long long ll;
const ll lim=34567+10;
const ll inf=4e16;
ll dp[lim];
ll v[lim];
int main()
{
    ll n,t;
    in>>n>>t;
    for(ll i=1;i<=n;++i)
    {
        in>>v[i];
        dp[i]=-inf;
        v[i]+=v[i-1];
        for(ll j=0;j<i;++j)
            dp[i]=max(dp[i],dp[j]+i*(v[i]-v[j])-t);
    }
    out<<dp[n]<<'\n';
    return 0;
}