text: ﻿function original() {
  function f(n){return n==0?1:n*f(n-1)}a=arguments[0];return f(2*a)/((a+1)*f(a)*4)
  }
  
  
  
  function solve() {
      function fact(num) {
          return num == 0 ? 1 : num * fact(num - 1);
      }
  
      input = arguments[0];
  
      var answer = fact(2 * input) / (fact(1 + input) * fact(input) * 2);
      return answer
  }
  
  (function(a){return[1,1,2,5,14,42,132,429,1430,4862,16796,58786][a[0]]/2})