output_description: If he can achieve the objective, print `OK`; if he cannot, print `NG`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      K
      A B
attempt: a, b, n = map(int, input().split())
  ans = int((a * n) / b) - a * int(n / b)
  n = n - 1
  ans = max(ans, int((a * n) / b) - a * int(n / b))
  n = n - 2
  ans = max(ans, int((a * n) / b) - a * int(n / b))
  n = n - 3
  ans = max(ans, int((a * n) / b) - a * int(n / b))
  n = min(n, 1)
  ans = max(ans, int((a * n) / b) - a * int(n / b))
  n = min(n, 2)
  ans = max(ans, int((a * n) / b) - a * int(n / b))
  n = min(n, 3)
  ans = max(ans, int((a * n) / b) - a * int(n / b))
  print(ans)
  
problem_description: Statement
  
  Takahashi the Jumbo will practice golf.
  
  His objective is to get a carry distance that is a multiple of K, while he can
  only make a carry distance of between A and B (inclusive).
  
  If he can achieve the objective, print `OK`; if he cannot, print `NG`.
samples: [{"input": "7\n    500 600", "output": "OK\n    \n\nAmong the multiples of 7, for example, 567 lies between 500 and 600.\n\n* * *"}, {"input": "4\n    5 7", "output": "NG\n    \n\nNo multiple of 4 lies between 5 and 7.\n\n* * *"}, {"input": "1\n    11 11", "output": "OK"}]