#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int n, m; cin >> n >> m;
  if (n == 1) {
    cout << 1 << '\n';
    return 0;
  }
  if (m == 1) {
    cout << n << '\n';
    return 0;
  }
  vector<ll> a{1, 2};
  while (a.size() < n && a.back() * 2 - 1 <= m) {
    const ll nxt = a.back() * 2 - 1;
    a.emplace_back(nxt);
  }
  FOR(i, 2, a.size()) {
    vector<ll> b = a;
    b[i] = b[i - 1] * 2;
    FOR(j, i + 1, a.size()) b[j] = b[j - 1] * 2 - 1;
    if (b.back() <= m) a.swap(b);
  }
  cout << accumulate(ALL(a), 0LL) + (n - a.size()) << '\n';
  return 0;
}