output_description: Print the number of the different possible sums.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N A B
attempt: n, a, b = map(int, input().split())
  s = 0
  if b >= a:
      s = (n - 2) * b - (n - 2) * a + 1
  print(s)
  
problem_description: Statement
  
  Snuke has N integers. Among them, the smallest is A, and the largest is B. We
  are interested in the sum of those N integers. How many different possible
  sums there are?
samples: [{"input": "4 4 6", "output": "5\n    \n\nThere are five possible sums: 18=4+4+4+6, 19=4+4+5+6, 20=4+5+5+6, 21=4+5+6+6\nand 22=4+6+6+6.\n\n* * *"}, {"input": "5 4 3", "output": "0\n    \n\n* * *"}, {"input": "1 7 10", "output": "0\n    \n\n* * *"}, {"input": "1 3 3", "output": "1"}]