#include <iostream>
#include <fstream>
using namespace std;

int main()
{int n,i,x,y,o;
    ifstream f("ciur.in");
    ofstream g("ciur.out");
    f>>n;
    o=0;
    for(i=1;i<=n;i++)
    {
        x=i;y=n;
        while(x!=y)
            if(x>y)
            x=x-y;
        else
            y=y-x;
        if(x==1)o++;


    }g<<o;
    return 0;
}