#include <bits/stdc++.h>
using namespace std;
const int inf = 2147483647;
const double PI = acos(-1.0);
const double e = 2.718281828459;
const int mod = 1000000007;
#pragma comment(linker, "/STACK:102400000,102400000")
double a[20][20];
int main() {
  int n, t, i, j;
  while (cin >> n >> t) {
    memset(a, 0, sizeof(a));
    a[1][1] = t * 1.0;
    int ans = 0;
    for (i = 1; i <= n; ++i) {
      for (j = 1; j <= i; ++j) {
        double x = a[i][j] - 1;
        if (x >= 0) {
          ans++;
          a[i + 1][j] += x / 2;
          a[i + 1][j + 1] += x / 2;
        }
      }
    }
    cout << ans << endl;
  }
}
