#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, t, count = 0;
  cin >> n >> t;
  double cup[15][15] = {0};
  cup[0][0] = t;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j <= i; j++) {
      if (cup[i][j] >= 1) {
        count++;
        cup[i + 1][j] += (cup[i][j] - 1) / 2.0;
        cup[i + 1][j + 1] += (cup[i][j] - 1) / 2.0;
      }
    }
  }
  cout << count << endl;
  return 0;
}
