#include <bits/stdc++.h>
int main() {
  int n, t;
  int i, j;
  int count;
  double glass[15][15];
  scanf("%d%d", &n, &t);
  memset(glass, 0, sizeof(glass));
  glass[1][1] = t * 1.0;
  count = 0;
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= i; j++) {
      if (glass[i][j] >= 1.0) {
        glass[i + 1][j] += (glass[i][j] - 1) / 2.0;
        glass[i + 1][j + 1] += (glass[i][j] - 1) / 2.0;
        count++;
      }
    }
  }
  printf("%d\n", count);
  return 0;
}
