#include <bits/stdc++.h>
using namespace std;
long double a[100][100];
int main() {
  int n, t;
  cin >> n >> t;
  a[1][1] = t - 1;
  int ans = 0;
  if (t >= 1) ans++;
  for (int i = 2; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      a[i][j] = (a[i - 1][j] + a[i - 1][j - 1]) / 2 - 1;
      if (a[i][j] >= 0) ans++;
      if (a[i][j] < 0) a[i][j] = 0;
    }
  }
  cout << ans;
}
