#include <stdio.h>

int prime(long long int value)
{
   unsigned int divisor = 3;
   unsigned int square  = divisor * divisor;

   if (value == 2)   return 1;
   if (value == 3)   return 1;
   if (!(value & 1)) return 0;	/* even */

   while (square < value && value % divisor) {
      ++divisor;
      square += 4 * divisor;
      ++divisor;
   }

   return value % divisor != 0;
}

int main() {
  long long int p = 3;
  long long int i = 2;
  while (p < 1000000) {
    if (prime(p)) {
      i = i + p;
    }
    p+=2;
  }
  printf("%llu",i);
  return 0;
}