static Dictionary<int, int> dic = new Dictionary<int, int>();


       private static int Test(int n)
       {

           if(!dic.ContainsKey(1))
           {

           dic.Add(1, 1);
           }
           if (!dic.ContainsKey(2))
           {
               dic.Add(2, 1);
           }
           for (int i = 3; i <= n; i++)
           {
               if (!dic.ContainsKey(i))
               {
                   dic[i] = dic[i - 1] + dic[i - 2];
               }
           }


           return dic[n];
       }