#include <stdio.h>
#define MAX 2000000

int table[MAX+1]={0};
int primes[MAX];

int main()
{
	int nPrimes,i,j;
	long long sum=0;
	for (i=2;i<=MAX;++i){
		if (table[i]==0){
			primes[nPrimes]=i;
			nPrimes++;
			sum+=i;
		}
		//sieve
		for (j=2;j<=primes[nPrimes-1];++j){
			if (i*j>MAX)
				break;
			else
				table[i*j]=1;
		}
	}
	printf("%lld\n",sum);
	return 0;
}