

import math


def 			__UpperCamelCase    (lowerCAmelCase					:  int     )     ->  bool:

      if 1 < number < 4:
            # 2 and 3 are primes
            return True
      elif number < 2 or number % 2 == 0 or number % 3 == 0:
            # Negatives, 0, 1, all even numbers, all multiples of 3 are not primes
            return False

      # All primes number are in format of 6k +/- 1
      for i in range(5,    int(math.sqrt(lowerCAmelCase     ) + 1     ),    6     ):
            if number % i == 0 or number % (i + 2) == 0:
                  return False
      return True


def 			__UpperCamelCase    (lowerCAmelCase					:  int = 2_000_000     )     ->  int:
      return sum(num for num in range(3,    lowerCAmelCase,    2     ) if is_prime(lowerCAmelCase     )     ) + 2 if n > 2 else 0


if __name__ == "__main__":
  print(F'''{solution() = }''')






from math import floor, sqrt


def 			__UpperCamelCase    (lowerCAmelCase					:  int     )     ->  int:
      A    =				0.0
      A    =				1.0
      A    =				int(sqrt(lowerCAmelCase     )     )
      A    =				root
      A    =				0
      while integer_part != 2 * root:
            A    =				denominator * integer_part - numerator
            A    =				(n - numerator**2) / denominator
            A    =				int((root + numerator) / denominator     )
            period += 1
      return period


def 			__UpperCamelCase    (lowerCAmelCase					:  int = 10_000     )     ->  int:
      A    =				0
      for i in range(2,    n + 1     ):
            A    =				sqrt(lowerCAmelCase     )
            if sr - floor(lowerCAmelCase     ) != 0 and continuous_fraction_period(lowerCAmelCase     ) % 2 == 1:
                  count_odd_periods += 1
      return count_odd_periods


if __name__ == "__main__":
  print(F'''{solution(int(input().strip()))}''')



