

def 		_lowercase (     lowercase__   ,	lowercase__						):
      __lowerCAmelCase					:						str					=					[0 for i in range(r + 1						)]
      # nc0 = 1
      __lowerCAmelCase					:						int					=					1
      for i in range(1   ,	n + 1						):
            # to compute current row from previous row.
            __lowerCAmelCase					:						List[str]					=					min(lowercase__   ,	lowercase__						)
            while j > 0:
                  c[j] += c[j - 1]
                  j -= 1
      return c[r]







print(binomial_coefficient(n=10, r=5))





def 		_lowercase (     lowercase__						):
      if not all(x.isalpha() for x in string						):
            raise ValueError('''String must only contain alphabetic characters.'''						)

      __lowerCAmelCase					:						int					=					sorted(string.lower()						)
      return len(lowercase__						) == len(set(lowercase__						)						)


if __name__ == "__main__":
 _UpperCamelCase 			=		input("Enter a string ").strip()

 _UpperCamelCase 			=		is_isogram(input_str)
 print(F"{input_str} is {'an' if isogram else 'not an'} isogram.")


