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#include <algorithm>
#include <cstdio>
#include <vector>

// Logging.
const bool logging_enabled = false;

// Constants.
const int MAX_BITS = 61;
const long long INF = 1000000000000000001LL;
const int MAX_NUMS = 201;

// Newton symbol.
long long C[MAX_BITS+1][MAX_BITS+1];

// How many numbers <= n with b bits are there?
long long CountNumbersWithBits2(long long n, int b) {
  if (logging_enabled) printf("Count(%lld, %d)\n", n, b);
  // Corner case.
  if (n == 0) {
    if (b == 0) return 1;
    else return 0;
  }

  long long res = 0;
  auto num_bits = 0;
  for (int i = 0; i < MAX_BITS; ++i) {
    if ((1LL << i) & n) ++num_bits;
  }
  if (logging_enabled) printf("num_bits(%lld) = %d\n", n, num_bits);
  int pos = 0;
  int passed_bits = 0;
  while (n) {
    long long current_bit = n & 1;
    n >>= 1;
    if (current_bit) {
      ++passed_bits;
      if (b - num_bits + passed_bits >= 0) {
        res += C[pos][b - num_bits + passed_bits];
      }
    }
    ++pos;
  }
  if (num_bits == b) ++res;
  if (logging_enabled) printf(" = %lld\n",  res);
  return res;
}

// How many numbers <= n with b bits are there?
long long CountNumbersWithBits(long long n, int b) {
  // Corner case.
  if (n == 0) {
    if (b == 0) return 1;
    else return 0;
  }

  std::vector<bool> bits;
  while (n) {
    bits.push_back(n & 1);
    n >>= 1;
  }

  long long res = 0;
  // Starting with the most significant bit.
  std::reverse(bits.begin(), bits.end());
  int passed_bits = 0;
  for (int i = 0; i < bits.size() && passed_bits <= b; ++i) {
    if (bits[i]) {
      // Assume we flipped the bit to 0.
      res += C[bits.size() - i - 1][b - passed_bits];
      ++passed_bits;
    }
  }
  if (passed_bits == b) ++res;
  return res;
}

// What is the lowest number higher than n with b bits?
long long NextHigherWithBits(long long n, int b) {
  // printf("NextHigherWithBits(%lld, %d)\n", n, b);
  long long base = CountNumbersWithBits2(n, b);

  long long l = n + 1, u = INF, res = -1;
  while (l <= u) {
    long long m = (l + u) / 2;
    if (CountNumbersWithBits2(m, b) > base) {
      res = m;
      u = m - 1;
    } else {
      l = m + 1;
    }
  }
  return res;
}

int n;
long long m;
long long a[MAX_NUMS];

// (value, last multiplier)
using Solution = std::pair<long long, long long>;

std::vector<Solution> dp[MAX_NUMS][MAX_BITS];

int main() {
  // Precalculate C(n, k).
  C[0][0] = 1;
  for (int i = 1; i <= MAX_BITS; ++i) {
    for (int j = 0; j <= i; ++j) {
      C[i][j] = C[i-1][j];
      if (j > 0) C[i][j] += C[i-1][j-1];
    }
  }

  /*
  long long n;
  int b;
  scanf("%lld%d", &n, &b);
  printf("%lld\n", NextHigherWithBits(n, b));
  */

  scanf("%d%lld", &n, &m);
  for (int i = 0; i < n; ++i) scanf("%lld", &a[i]);

  if (logging_enabled) printf("Read input.\n");

  // Initialize dp[0].
  dp[0][0].push_back({0LL, 0LL});
  for (int i = 1; i < MAX_BITS; ++i) {
    long long current_last = 0;
    for (int sol_idx = 0; sol_idx < n; ++sol_idx) {
      current_last = NextHigherWithBits(current_last, i);
      if (current_last == -1 || current_last > m) break;
      dp[0][i].push_back({i*a[0], current_last});
      if (logging_enabled) printf("Pushing {%lld, %lld} to dp[%d][%d]\n", i*a[0], current_last, 0, i);
    }
  }

  // Calculate dp[1..n-1].
  for (int i = 1; i < n; ++i) {
    for (int b = 0; b < MAX_BITS; ++b) {
      // Calculate dp[i][b].
      for (int c = 0; c < MAX_BITS; ++c) {
        for (const auto& prev_sol : dp[i-1][c]) {
          Solution sol;
          sol.second = NextHigherWithBits(prev_sol.second, b);
          if (sol.second != -1 && sol.second <= m) {
            sol.first = prev_sol.first + b * a[i];
            dp[i][b].push_back(sol);
          }
        }
      }
      std::sort(dp[i][b].begin(), dp[i][b].end());
      std::reverse(dp[i][b].begin(), dp[i][b].end());
      if (dp[i][b].size() > n) {
        dp[i][b].erase(dp[i][b].begin() + n, dp[i][b].end());
      }
      if (!dp[i][b].empty() && logging_enabled) {
        if (logging_enabled) printf("Calculated non-empty dp[%d][%d]\n", i, b);
        for (const auto& sol : dp[i][b]) {
          if (logging_enabled) printf("{%lld, %lld}\n", sol.first, sol.second);
        }
      }
    }
  }

  long long res = -INF;
  for (int b = 0; b < MAX_BITS; ++b) {
    for (const auto& sol : dp[n-1][b]) {
      res = std::max(res, sol.first);
    }
  }

  printf("%lld\n", res);

  return 0;
}