primes = [2]
counter = 1
while counter <= 2000000:
    counter += 2
    for x in primes:
        if x * x > counter:
            # print(str(counter) + " found")
            primes += [counter]
            break
        elif counter % x == 0:
            break
counter = 0
for x in primes:
    counter += x
print(counter)