#include <bits/stdc++.h>
using namespace std;
const int maxn = 5e2;
double f[20][20];
int n, t, i, j, ans;
int main() {
  scanf("%d%d", &n, &t);
  f[1][1] = t;
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= n; j++)
      if (f[i][j] >= 1) {
        ans++;
        f[i][j]--;
        f[i + 1][j] += f[i][j] / 2;
        f[i + 1][j + 1] += f[i][j] / 2;
        f[i][j] = 1;
      }
  }
  printf("%d", ans);
  return 0;
}
