#include <bits/stdc++.h>
using namespace std;
const int N = 55;
long long dp[N][N];
long long solve(int n, int h) {
  if (n == 0 || h == 0) {
    return n + h == 0;
  }
  long long& res = dp[n][h];
  if (res != -1) {
    return res;
  }
  res = 0;
  for (int m = 1; m <= n; ++m) {
    for (int i = 0; i < h; ++i) {
      res += solve(m - 1, h - 1) * solve(n - m, i);
    }
    for (int i = 0; i < h - 1; ++i) {
      res += solve(m - 1, i) * solve(n - m, h - 1);
    }
  }
  return res;
}
int main() {
  int n, h;
  scanf("%d %d", &n, &h);
  memset(dp, -1, sizeof(dp));
  long long ans = 0;
  for (int i = h; i <= n; ++i) {
    ans += solve(n, i);
  }
  printf("%lld\n", ans);
  return 0;
}
