#include <bits/stdc++.h>
using namespace std;
double c[11][11];
int n, t;
int main() {
  scanf("%d%d", &n, &t);
  c[1][1] = t;
  for (int i = 2; i <= n; i++)
    for (int j = 1; j <= i; j++)
      c[i][j] =
          max(c[i - 1][j - 1] - 1, 0.0) / 2 + max(c[i - 1][j] - 1, 0.0) / 2;
  int ans = 0;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= i; j++)
      if (c[i][j] >= 1) ans++;
  printf("%d\n", ans);
  return 0;
}
