output_description: Print the number of ways to select cards such that the average of the written
  integers is exactly A.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      N A
      x_1 x_2 ... x_N
attempt: import itertools↲                                 
  ↲                                                   
  n, a = map(int, input().split())↲                   
  array = [int(x) for x in input().split()]↲          
  ↲                                                   
  array2 = []↲                                        
  tmp = 0↲                                            
  for i in array:↲                                    
      tmp += i↲                                       
      array2.append(tmp)↲                             
  ↲                                                   
  ans = 0↲                                            
  for pickup in range(1, n+1):↲                       
      tmp_gen = itertools.combinations(array, pickup)↲
      for i in tmp_gen:↲                              
      	if sum(i) == a*pickup:↲                     
  		ans += 1↲                               
  print(ans)↲
problem_description: Statement
  
  Tak has N cards. On the i-th (1 \leq i \leq N) card is written an integer x_i.
  He is selecting one or more cards from these N cards, so that the average of
  the integers written on the selected cards is exactly A. In how many ways can
  he make his selection?
samples: [{"input": "4 8\n    7 9 8 9", "output": "5\n    \n\n  * The following are the 5 ways to select cards such that the average is 8:\n    * Select the 3-rd card.\n    * Select the 1-st and 2-nd cards.\n    * Select the 1-st and 4-th cards.\n    * Select the 1-st, 2-nd and 3-rd cards.\n    * Select the 1-st, 3-rd and 4-th cards.\n\n* * *"}, {"input": "3 8\n    6 6 9", "output": "0\n    \n\n* * *"}, {"input": "8 5\n    3 6 2 8 7 6 5 9", "output": "19\n    \n\n* * *"}, {"input": "33 3\n    3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3", "output": "8589934591\n    \n\n  * The answer may not fit into a 32-bit integer."}]