#include <iostream>
#include <fstream>
using namespace std;
bool lnko(int a, int b)
{
    while(a!=b)
    {
        if(a>b) a-=b;
        else b-=a;
    }
    if(a==1) return true;
    return false;
}
int main()
{
    int n, d = 0;
    ifstream f("fractii.in");
    f>>n;
    f.close();
    d = n;
    for(int i = 2;i<=n;i++)
        if(i%2 == 0) d = d+n-(n/2);
        else d = d+n-(n/3);
    ofstream g("fractii.out");
    g<<d;
    g.close();
    return 0;
}