#include <bits/stdc++.h>
using namespace std;
double dp[60][60];
int main() {
  long long int n, i, j, t, c = 0;
  cin >> n >> t;
  dp[1][1] = t;
  for (i = 2; i <= n; i++) {
    for (j = 1; j <= i; j++) {
      dp[i][j] = max(0.0, (dp[i - 1][j - 1] - 1) / 2.0) +
                 max(0.0, (dp[i - 1][j] - 1) / 2.0);
      if (dp[i][j] >= 1) c++;
    }
  }
  if (dp[1][1] >= 1) c++;
  cout << c << endl;
  return 0;
}
