#include<stdio.h>
int v[300];
int a[30001];
int main()
{ 
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);
	int n,m=1,f=0,i=1,p=0,o=2,r=0,s=0;
	scanf("%d",&n);
       while(n>0){
            while(o*o<=n){ 
             if(n%o==0){ 
             a[o]++; 
             n=n/o; 
             if(o>r){
					r=o;
				}
}else{ 
o++; 
if(o==r)
s++;
} 
}
o=2;
while(o<=r){
if(a[o]!=0){
	while(i<=s){
	v[i]=o;
	i++;
}
}
o++;
}
m=m*n;
for(i=1;i!=0;i++){
	m=m*(1-1/v[i]);
}
f=f+m;
n--;
m=1;
o=2;
i=1;
s=0;
r=0;
}
printf("%d",f);
return 0;
}