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"""

https://projecteuler.net/problem=10

Problem Statement:

The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.

Find the sum of all the primes below two million using Sieve_of_Eratosthenes:

The sieve of Eratosthenes is one of the most efficient ways to find all primes

smaller than n when n is smaller than 10 million. Only for positive numbers.

"""

def prime_sum(n: int) -> int:

"""Returns the sum of all the primes below n.

>>> prime_sum(2_000_000)

142913828922

>>> prime_sum(1_000)

76127

>>> prime_sum(5_000)

1548136

>>> prime_sum(10_000)

5736396

>>> prime_sum(7)

>>> prime_sum(7.1) # doctest: +ELLIPSIS

Traceback (most recent call last):

...

TypeError: 'float' object cannot be interpreted as an integer

>>> prime_sum(-7) # doctest: +ELLIPSIS

Traceback (most recent call last):

...

IndexError: list assignment index out of range

>>> prime_sum("seven") # doctest: +ELLIPSIS

Traceback (most recent call last):

...

TypeError: can only concatenate str (not "int") to str

"""

list_ = [0 for i in range(n + 1)]

list_[0] = 1

list_[1] = 1

for i in range(2, int(n ** 0.5) + 1):

if list_[i] == 0:

for j in range(i * i, n + 1, i):

list_[j] = 1

s = 0

for i in range(n):

if list_[i] == 0:

s += i

return s

if __name__ == "__main__":

# import doctest

# doctest.testmod()

print(prime_sum(int(input().strip())))

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