output_description: Print the number of integers between A and B (inclusive) that can be evenly
  divided by neither C nor D.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B C D
attempt: A, B, C, D = list(map(int, input().split()))
  a1 = (A - 1) // C
  a2 = (A - 1) // D
  a3 = (A - 1) // (C * D)
  a = (A - 1) - (a1 + a2 - a3)
  b1 = B // C
  b2 = B // D
  b3 = B // (C * D)
  b = B - (b1 + b2 - b3)
  print(b - a)
  
problem_description: Statement
  
  You are given four integers A, B, C, and D. Find the number of integers
  between A and B (inclusive) that can be evenly divided by neither C nor D.
samples: [{"input": "4 9 2 3", "output": "2\n    \n\n5 and 7 satisfy the condition.\n\n* * *"}, {"input": "10 40 6 8", "output": "23\n    \n\n* * *"}, {"input": "314159265358979323 846264338327950288 419716939 937510582", "output": "532105071133627368"}]