output_description: Print his Inner Rating.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N R
attempt: import math
  
  n, a, b = map(int, input().split())
  c = 0
  for i in range(1, n + 1):
      c += (math.factorial(n) // (math.factorial(n - i) * math.factorial(i))) % (
          pow(10, 9) + 7
      )
  
  c = c - (math.factorial(n) // (math.factorial(n - a) * math.factorial(a))) % (
      pow(10, 9) + 7
  )
  c = c - (math.factorial(n) // (math.factorial(n - b) * math.factorial(b))) % (
      pow(10, 9) + 7
  )
  print(c)
  # TLE
  
problem_description: Statement
  
  Takahashi is a member of a programming competition site, _ButCoder_.
  
  Each member of ButCoder is assigned two values: **Inner Rating** and
  **Displayed Rating**.
  
  The Displayed Rating of a member is equal to their Inner Rating if the member
  has participated in 10 or more contests. Otherwise, the Displayed Rating will
  be their Inner Rating minus 100 \times (10 - K) when the member has
  participated in K contests.
  
  Takahashi has participated in N contests, and his Displayed Rating is R. Find
  his Inner Rating.
samples: [{"input": "2 2919", "output": "3719\n    \n\nTakahashi has participated in 2 contests, which is less than 10, so his\nDisplayed Rating is his Inner Rating minus 100 \\times (10 - 2) = 800.\n\nThus, Takahashi's Inner Rating is 2919 + 800 = 3719.\n\n* * *"}, {"input": "22 3051", "output": "3051"}]