#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const double PI = acos(-1.0);
const long long inf = 1e18;
const int N = 1e6 + 4;
int n, t;
double a[20][20];
void fun() {
  a[1][1] += 1;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      if (a[i][j] > 1) {
        a[i + 1][j] += (a[i][j] - 1) / 2;
        a[i + 1][j + 1] += (a[i][j] - 1) / 2;
        a[i][j] = 1;
      }
    }
  }
}
int main() {
  scanf("%d%d", &n, &t);
  for (int i = 1; i <= t; i++) fun();
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++)
      if (a[i][j] >= 1) ans++;
  }
  printf("%d\n", ans);
  return 0;
}
