#include <bits/stdc++.h>
int main() {
  double a[15][15];
  memset(a, 0, sizeof(a));
  int n, t, count = 0;
  scanf("%d%d", &n, &t);
  a[1][1] = t;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      a[i][j] += 0.5 * ((a[i - 1][j - 1] >= 1 ? a[i - 1][j - 1] - 1 : 0) +
                        (a[i - 1][j] >= 1 ? a[i - 1][j] - 1 : 0));
      if (a[i][j] >= 1) {
        count++;
      }
    }
  }
  printf("%d", count);
  return 0;
}
