#include <stdio.h>
int Function(int n)
{
    int k,SumTime = 0;
    if(n>12)
    {
         SumTime = ((n/12)*4)+2;
         return SumTime;
    }
    else 
    {
        return 2;
    }


}
int main()
{
    int n = 0;
    scanf("%d",&n);
    int time = Function(n);
    printf("%d\n",time);
    return 0;
}