text: """
      2407 : 조합
      URL : https://www.acmicpc.net/problem/2407
      Input :
          100 6
      Output :
          1192052400
  """
  
  MAX_N = 101
  MAX_M = 101
  
  cache = [[-1 for _ in range(MAX_M)] for _ in range(MAX_N)]
  cache[0][0] = 1
  cache[1][0] = 1
  cache[1][1] = 1
  
  
  def binomial(n, m):
      if m == 0 or m == n:
          return 1
  
      if cache[n][m] != -1:
          return cache[n][m]
  
      cache[n][m] = binomial(n - 1, m - 1) + binomial(n - 1, m)
      return cache[n][m]
  
  
  n, m = map(int, input().split(' '))
  print(binomial(n, m))
  