#include <bits/stdc++.h>
using namespace std;
using db = long double;
using pll = pair<long long, long long>;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t, i, x, j, y, z, k, n;
  cin >> n >> t;
  vector<vector<db>> v;
  for (i = 1; i < n + 1; i += 1) {
    std::vector<db> t;
    for (j = 0; j < i; j += 1) t.push_back(0);
    v.push_back(t);
  }
  vector<db> temp(n + 10);
  v.push_back(temp);
  v[0][0] += t;
  z = 0;
  for (i = 0; i < n; i += 1) {
    for (j = 0; j < i + 1; j += 1) {
      if (v[i][j] >= 1) {
        z++;
        db k = (v[i][j] - 1.0) / 2.0;
        v[i + 1][j] += k;
        v[i + 1][j + 1] += k;
        v[i][j] -= 2 * k;
      }
    }
  }
  cout << z << '\n';
  ;
  42;
}
