From 27d663a4dfd4fc3ac075a7a3505972251d59f27e Mon Sep 17 00:00:00 2001
From: Baoshuo <i@baoshuo.ren>
Date: Mon, 17 Oct 2022 10:04:44 +0800
Subject: [PATCH] D - How many trees?

https://codeforces.com/contest/9/submission/176628922
---
 Codeforces/9/D/D.cpp | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 Codeforces/9/D/D.cpp

diff --git a/Codeforces/9/D/D.cpp b/Codeforces/9/D/D.cpp
new file mode 100644
index 00000000..609460c0
--- /dev/null
+++ b/Codeforces/9/D/D.cpp
@@ -0,0 +1,33 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 40;
+
+int n, h;
+long long f[N][N];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> h;
+
+    for (int i = 0; i <= n; i++) {
+        f[0][i] = 1;
+    }
+
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= n; j++) {
+            for (int k = 0; k < i; k++) {
+                f[i][j] += f[k][j - 1] * f[i - k - 1][j - 1];
+            }
+        }
+    }
+
+    cout << f[n][n] - f[n][h - 1] << endl;
+
+    return 0;
+}