#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, t, i, j, c = 0;
  long double d;
  cin >> n >> t;
  auto arr = new long double*[n];
  for (i = 0; i < n; i++) arr[i] = new long double[n]{};
  while (t--) {
    arr[0][0] += 1.L;
    for (i = 0; i < n - 1; i++)
      for (j = 0; j <= i; j++)
        if (arr[i][j] > 1.L) {
          d = arr[i][j] - 1.L;
          arr[i][j] = 1.L;
          arr[i + 1][j] += d / 2.L;
          arr[i + 1][j + 1] += d / 2.L;
        }
  }
  for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++)
      if (arr[i][j] - 1.L > -1e-8) ++c;
  }
  cout << c;
  return 0;
}
