#include<cstdio>
using namespace std;
long long n,ans;
int main()
{
    while(1)
    {
        scanf("%lld",&n);
        if(!n) break;
        ans=n;
        for(long long i=2;i*i<=n;i++)
         if(n%i==0)
         {
             while(n%i==0) n/=i;
             ans=ans/i*(i-1);
         }
        if(n>1) ans=ans/n*(n-1);
        printf("%lld\n",ans);
    }
}

#include<cstdio>
using namespace std;
int main()
{
    long long n,ans;
    while(1)
    {
        scanf("%lld",&n);
        if(!n) return 0;
        ans=n;
        if(n%2==0)
        {
            while(n%2==0) n/=2;
            ans=ans/2;
        }
        for(long long i=3;i*i<=n;i+=2)
           if(n%i==0)
            {
                while(n%i==0) n/=i;
                ans=ans/i*(i-1);
            }
        if(n>1) ans=ans/n*(n-1);
        printf("%lld\n",ans);
    }
}