#include <cstdio>
using namespace std;
int main(void)
{
 unsigned long long int a;
 while(scanf("%u",&a)!=EOF){
   unsigned long long int i = 2,sum = 0;
     while (i <= a)
     {
       while (a % i == 0)
       {
         sum+=i;
         a /= i;
       }
       if(i==2)
         i++;
       else
         i+=2;
     }
     printf("%u\n",sum);
 }
}