#include <bits/stdc++.h>
using namespace std;
long double dp[15][15];
int main() {
  int n, t;
  cin >> n >> t;
  dp[1][1] = t;
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      if (dp[i][j] + 1e-12 >= 1) ans++;
      long double r = max(dp[i][j] - 1, (long double)0);
      dp[i + 1][j] += r * 0.5;
      dp[i + 1][j + 1] += r * 0.5;
    }
  }
  cout << ans << endl;
  return 0;
}
