import math

limit = 2000000

crosslimit = int(math.sqrt(limit))

#sieve = [False] * limit

sieve = [False for i in range(0, limit)]

for i in range(4, limit + 1, 2):

    sieve[i-1] = True

for i in range(3, crosslimit + 1, 2):

    if not sieve[i-1]:

        for m in range(i*i, limit+1, 2*i):

            sieve[m-1] = True

MySum = 0

for i in range(2, limit+1):

    if not sieve[i-1]:

        MySum += i

print(MySum)