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// while (clock()<=69*CLOCKS_PER_SEC)
// #pragma comment(linker, "/stack:200000000")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("Ofast")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
// #pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define SZ(x) ((int)(x).size())
#define ALL(x) x.begin(),x.end()
#define all(x) x.begin(),x.end()
#define fi first
#define se second
#define _upgrade ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define erase_duplicates(x) sort(all(x)); (x).resize(distance((x).begin(), unique(all(x))));


using namespace std;
using namespace __gnu_pbds;
template<typename T>
using ordered_set = tree<
T,
null_type,
less<T>,
rb_tree_tag,
tree_order_statistics_node_update>;

//X.find_by_order(k); - zwraca iterator na k-ty element (numeracja od zerowego)
//X.order_of_key(k); - zwraca liczbę elementów ostro mniejszych niż k

typedef long long LL;
typedef pair<int,int> PII;
typedef pair<LL,LL> PLL;
typedef vector<PII> VPII;
typedef vector<PLL> VPLL;
typedef vector<LL> VLL;
typedef vector<int> VI;
typedef vector<string> VS;
typedef vector<char> VC;
typedef long double LD;
typedef pair<LD,LD> PLD;
typedef vector<LD> VLD;
typedef vector<PLD> VPLD;

template<class TH> void _dbg(const char *sdbg, TH h){ cerr<<sdbg<<" = "<<h<<endl; }
template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) {
  while(*sdbg!=',')cerr<<*sdbg++;
  cerr<<" = "<<h<<", "; _dbg(sdbg+1, a...);
}

#ifdef LOCAL
#define dbg(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#else
#define dbg(...)
#define cerr if(0)cout
#endif

const int maxn = (200)+7;
const int maxk = 61;
const int inf = (1e9)+7;
const LL LLinf = ((LL)1e18)+7LL;
const LD eps = 1e-9;
const LL mod = 1e9+7;

// ***************************** CODE ***************************** //

LL dp[maxn][maxn][maxk][2];
LL tab[maxn];
LL b[maxn];

LL suma(int l, int p)
{
  if(l <= p)
    return tab[p] - tab[l - 1];
  return 0LL;
}

LL go(int l, int p, int bit, bool zgodne)
{
  if(p < l) return 0;
  if(bit == -1)
  {
    if(l == p)
      return 0;
    return -LLinf;
  }
  if(dp[l][p][bit][zgodne] == LLinf)
  {
    LL cur = -LLinf;
    if(zgodne == 0 or b[bit] == 1)
    {
      for(int i = l - 1;i <= p;i++) // [l, i], [i + 1, p]
        cur = max(cur, go(l, i, bit - 1, 0) + go(i + 1, p, bit - 1, zgodne) + suma(i + 1, p));
    }
    else
      cur = go(l, p, bit - 1, zgodne);
    dp[l][p][bit][zgodne] = cur;
    // dbg(l, p, bit, zgodne, cur);
  }
  return dp[l][p][bit][zgodne];
}

int main()
{
	_upgrade
  int n;
  LL m;
  cin>>n>>m;
  for(int i = 0;i < maxk;i++)
    b[i] = ((m >> i) & 1);
  for(int i = 1;i <= n;i++)
  {
    cin>>tab[i];
    tab[i] += tab[i - 1];
  }
  for(int i = 0;i <= n;i++)
    for(int j = 0;j <= n;j++)
      for(int k = 0;k < maxk;k++)
        for(int f = 0;f < 2;f++)
          dp[i][j][k][f] = LLinf;
  cout<<go(1, n, maxk - 1, 1);
	return 0;
}