#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<deque>
#include<fstream>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>

using namespace std;

#define dbg(x) (cout<<#x<<" = "<<(x)<<'\n')
#ifdef HOME
const string inputFile = "input.txt";
const string outputFile = "output.txt";
#else
const string problemName = "euro";
const string inputFile = problemName + ".in";
const string outputFile = problemName + ".out";
#endif

typedef long long int lld;
typedef pair<int, int> PII;
typedef pair<int, lld> PIL;
typedef pair<lld, int> PLI;
typedef pair<lld, lld> PLL;

const int INF = (1LL << 31) - 1;
const lld LINF = (1LL << 60) - 1;
const int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
const int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};
const int NMAX = 34567 + 5;

int N, T, M;
int S[NMAX];
lld DP[NMAX];
int V[NMAX];

int main() {
    int i, j, x;

#ifndef ONLINE_JUDGE
    freopen(inputFile.c_str(), "r", stdin);
    freopen(outputFile.c_str(), "w", stdout);
#endif

    scanf("%d%d", &N, &T);

    for(i = 1; i <= N; i++) {
        scanf("%d", &x);
        S[i] = S[i - 1] + x;
    }

    for(i = j = 1; i <= N; i++)
        if(S[i] - S[j - 1] < 0) {
            V[++M] = i;
            j = i + 1;
        }

    if(j <= N)
        V[++M] = N;

    for(i = 1; i <= M; i++) {
        DP[i] = -LINF;
        for(j = max((int)(i - sqrt(T) - 2), 1); j <= i; j++)
            DP[i] = max(DP[i], DP[j - 1] + (S[V[i]] - S[V[j - 1]]) * 1LL * V[i] - T);
    }

    printf("%lld\n", DP[M]);

    return 0;
}