#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, res;
  cin >> n;
  float m[n][n];
  for (int i = 0; i < n; i++)
    for (int j = 0; j < n; j++) m[i][j] = 0;
  cin >> m[0][0];
  for (int i = 0; i < n; i++)
    for (int j = 0; j < n; j++)
      if (m[i][j] >= 1) {
        res++;
        m[i + 1][j] += (m[i][j] - 1) / 2;
        m[i + 1][j + 1] += (m[i][j] - 1) / 2;
        m[i][j] = 1;
      }
  cout << res;
  return 0;
}
