#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define dbg(x) cerr << #x << " " << x << "\n"
#define pb push_back

const int N = 1e5, INF = 2e9;

int dp[1 + N];
int sum[1 + N];
int a[1 + N];

int main () {
    freopen ("euro.in", "r", stdin);
    freopen ("euro.out", "w", stdout);

    ios::sync_with_stdio (false);
    cin.tie (0); cout.tie (0);

    int n, t;
    cin >> n >> t;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sum[i] = sum[i - 1] + a[i];
    }

    for (int i = 1; i <= n; i++)
        dp[i] = -INF;
    dp[0] = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 0; j < i; j++)
            dp[i] = max (dp[i], dp[j] + (sum[i] - sum[j]) * i - t);
    }

    cout << dp[n] << "\n";
    return 0;
}