#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    int b,i,n,m1,m2,a,o;
    fstream f("fractii.in",ios::in);
    fstream g("fractii.out",ios::out);
    f>>b;
    for((i=1)&&(n=-b+2);i<b;b--)
    {
        for(a=2;i<b;i++)
        {
                if(i==1) n=n+1;
                else for(a=2;(a<=i)&&(o==0);a++)
                {
                    m1=b%a;
                    m2=i%a;
                    if((m1==0)&&(m2==0)) o=1;
                }
                if(o==0) n=n+1;
                o=0;
        }
        i=1;

    }
    n=n*2+1;
    g<<n;
    f.close();
    g.close();
    return 0;
}