#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base ::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long i, n, ans = 0, j;
  long double t;
  cin >> n >> t;
  long double g[n + 1][n + 1];
  memset(g, 0, sizeof(g));
  g[0][0] = t;
  for (i = 0; i < n; i++) {
    for (j = 0; j <= i; j++) {
      if (g[i][j] >= 1) {
        ++ans;
        g[i + 1][j] += (g[i][j] - 1) / 2;
        g[i + 1][j + 1] += (g[i][j] - 1) / 2;
      }
    }
  }
  cout << ans;
  return 0;
}
