//************************
// Bagheri. Naser
//ProjectEuler Problem #10
//************************
 #include <iostream>
#include <cmath>
using namespace std;


bool check(long long n) 
{
		  if(n == 2)
			return true;
		else if(n == 1)
			return false;
		if(n % 2 == 0)
			return false;

	for(int i = 3; i <=sqrt(n); i += 2)
	{
		if(n % i == 0)
		return false;
	}  
  return true;  
 }

int main()
{
	long long sum =0;
	for(long long i = 2; i<2000000; i++)
	{
		if(check(i)==true)
		{sum += i;}
	}
	   cout<<sum;
	return 0;}