#include <stdio.h>

int main()
{
    int n = 0;
    scanf("%d ",&n);
    int sun = 0;
    int he = 0;
    sun = (n/12);
    if ((sun==0)!=EOF)
        {
            he = sun*4+2;
        }
        else
        {
            he = 2;
        }
        printf("%d\n",he);

    return 0 ;

}