#include <vector>
#include <iostream>
 
unsigned long primes = 0;
 
int main() {
    int number = 10000000;
    std::vector<bool> sieve(number,false);
    sieve[0] = sieve[1] = true;
 
    for(int i = 2; i<number; i++) {
        if(!sieve[i]) {
            ++primes;
            for (int temp = 2*i; temp<number; temp += i)
                sieve[temp] = true;
        }
    }
    std::cout << "found: " << primes << " Primes\n";
    return 0;
}
 

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