def     _a				(      lowercase__  :			Dict ):







     '''simple docstring'''


     return sum(i for i in range(1     ,  number // 2 + 1 ) if number % i == 0 ) == number


if __name__ == "__main__":
      print("Program to check whether a number is a Perfect number or not...")
      SCREAMING_SNAKE_CASE__		:					Dict						=					int(input("Enter number: ").strip())
      print(F"""{number} is {"" if perfect(number) else "not "}a Perfect Number.""")




def     _a				(      lowercase__  :			int = 1_00_00_00 ):







     '''simple docstring'''


     SCREAMING_SNAKE_CASE__				:				str			=		[i - 1 for i in range(limit + 1 )]

     for i in range(2     ,  limit + 1 ):
          if phi[i] == i - 1:
               for j in range(2 * i     ,  limit + 1     ,  lowercase__ ):
                    phi[j] -= phi[j] // i

     return sum(phi[2 : limit + 1] )


if __name__ == "__main__":
      print(solution())



