#include <stdio.h>
using namespace std;
int a,n,cn,x=1,y=1,d;
int main()
{
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);
    scanf("%d%d",&a,&n);
    d=2;
    cn=a;
    while(d*d<=a)
    {
        if(a%d==0)
        {
            x=x*(d-1);
            y*=d;
            while(a%d==0)
                a/=d;
        }
        d++;
    }
    if(a!=1)
      a--;
    else a=cn*x/y;
    a--;
    printf("%d",a);
}