#include <stdio.h>

#define MAXN (1 << 16)
#define max(a,b) ((a) > (b) ? (a) : (b))

typedef long long llong;

const int SQRT = 380;

int N;
llong T, P, A[MAXN], S[MAXN], end[MAXN];
llong best[MAXN];

void baga_brute(void)
{
    int i, j;
    llong sum;

    for(i = 1; i <= N; i++)
    {
        best[i] = best[i-1]+A[i]*i, sum = A[i];
        for(j = i-1; j >= 1; j--)
        {
            sum += A[j];
            best[i] = max(best[i], sum*i+best[j-1]);
        }
        best[i] -= T;
    }
}

void solve(void)
{
    int i, j, sum;

    for(i = 1, sum = 0; i < N; i++)
    {
        sum += A[i];
        if(sum < 0)
            S[++P] = sum, end[P] = i, sum = 0;
    }
    sum += A[N], S[++P] = sum, end[P] = N;

    for(i = 1; i <= P; i++)
    {
        best[i] = (llong)S[i]*end[i]+best[i-1], sum = S[i];
        for(j = i-1; j >= i-SQRT && j >= 1; j--)
        {
            sum += S[j];
            best[i] = max(best[i], (llong)sum*end[i]+best[j-1]);
        }
        best[i] -= (llong)T;
    }
}

void read_data(void)
{
    int i;

    scanf("%d %lld\n", &N, &T);

    for(i = 1; i <= N; i++)
        scanf("%lld ", &A[i]);
}


void write_data(void)
{
    printf("%lld\n", best[P]);
}

int main(void)
{
    freopen("euro.in", "rt", stdin);
    freopen("euro.out", "wt", stdout);

    read_data();
//    solve();
    baga_brute();
    //write_data();

    printf("%lld\n", best[N]);
    
    return 0;
}