output_description: Print the maximum possible value of floor(Ax/B) - A × floor(x/B) for a non-
  negative integer x not greater than N, as an integer.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B N
attempt: A = list(map(int, input().split()))  # 入力のときに N を使う必要はありません
  i_max = 0
  i_count = 0
  j_count = 1
  
  for x in range(1, A[2] + 1):
      if i_max < ((A[0] * x) // A[1] - A[0] * (x // A[1])):
          i_max = (A[0] * x) // A[1] - A[0] * (x // A[1])
          i_count = x
      if (x - i_count) == 1:
          j_count = j_count + 1
      if j_count == 2:
          break
  
  print(i_count)
  
problem_description: Statement
  
  Given are integers A, B, and N.
  
  Find the maximum possible value of floor(Ax/B) - A × floor(x/B) for a non-
  negative integer x not greater than N.
  
  Here floor(t) denotes the greatest integer not greater than the real number t.
samples: [{"input": "5 7 4", "output": "2\n    \n\nWhen x=3, floor(Ax/B)-A\u00d7floor(x/B) = floor(15/7) - 5\u00d7floor(3/7) = 2. This is\nthe maximum value possible.\n\n* * *"}, {"input": "11 10 9", "output": "9"}]