#include <bits/stdc++.h>
using namespace std;
int t, n;
int x;
double a[1009][1009];
int main() {
  scanf("%d%d", &n, &t);
  a[1][1] = t;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++)
      if (a[i][j] >= 1) {
        x++;
        a[i + 1][j] += (a[i][j] - 1) / 2.0;
        a[i + 1][j + 1] += (a[i][j] - 1) / 2.0;
      }
  }
  cout << x;
  return 0;
}
