#include <bits/stdc++.h>
float a[11][11];
int main() {
  int n, t, i, j, dem = 0;
  scanf("%d%d", &n, &t);
  a[1][1] = t;
  for (i = 1; i <= n; i++) {
    for (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;
        dem++;
      }
    }
  }
  printf("%d", dem);
}
