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#include <bits/stdc++.h>


using namespace std;


const int N = 200;
const int BITS = 60;
const long long INF = 2e18;

long long dp[BITS + 1][2][N][N];

void maxify(long long &x, long long val) {
    x = max(x, val);
}

long long solve(int n, long long m, const vector <long long> &a) {
    for (int bits = 0; bits <= BITS; bits++) for (int ub = 0; ub < 2; ub++) {
        for (int l = 0; l < n; l++) for (int r = l; r < n; r++) {
            dp[bits][ub][l][r] = -INF;
        }
    }

    for (int ub = 0; ub < 2; ub++) for (int l = 0; l < n; l++) {
        dp[0][ub][l][l] = 0;
    }

    vector <bool> mBit(BITS);

    for (int bit = 0; bit < BITS; bit++) {
        mBit[bit] = m & (1LL << bit);
    }

    for (int bits = 0; bits < BITS; bits++) for (int ub = 0; ub < 2; ub++) {
        bool onlyZeros = ub && !mBit[bits];

        for (int l = 0; l < n; l++) for (int r = l; r < n; r++) {
            long long sumRight = 0;

            for (int mid = r; mid >= l - 1; mid--) {
                if (onlyZeros && mid < r) break;

                long long here = sumRight;

                if (mid >= l) {
                    sumRight += a[mid];
                }

                if (mid >= l) {
                    int ubLeft = ub && !mBit[bits];

                    long long hereLeft = dp[bits][ubLeft][l][mid];
                    if (hereLeft == -INF) {
                        continue;
                    }

                    here += hereLeft;
                }

                if (mid < r) {
                    int ubRight = ub;

                    long long hereRight = dp[bits][ubRight][mid + 1][r];
                    if (hereRight == -INF) {
                        continue;
                    }

                    here += hereRight;
                }

                maxify(dp[bits + 1][ub][l][r], here);
            }
        }
    }

    return dp[BITS][1][0][n-1];
}

int main() {
    ios_base::sync_with_stdio(false);

    int n; long long m;
    cin >> n >> m;

    vector <long long> a(n);
    for (auto &ai : a) {
        cin >> ai;
    }

    cout << solve(n, m, a);

    return 0;
}