#include stdio.h  
  
#define NMax 1000001  
  
char is[NMax];  
unsigned int n;  
unsigned long long tot[NMax];  
  
void ciur() {  
unsigned int i,j;  
 for (i=2; i=n; i++) {  
  if (is[i]==0)   i==nr prim  
   for (j=ii; j=n; j+=i)  
    is[j]=1;  j nu e nr prim  
 }  
}  
  
unsigned int totient(unsigned int x) {  
unsigned int i,j=0,k, l=1,pow=1;  
 if (is[x]==0) return x-1;  daca x nr prim, return x-1  
 k=x;  
 if (k%2==0) {  x == 2^j  k, k=1  
  while (k1 && k%2==0) {  
   j++; k=2;  
  }  
  return (1(j-1))tot[k];  return 2^(j-1)  totient[k]  
 }  
 for (i=3; k%i!=0; i+=2) {;}  
 while (k1 && k%i==0) {  
  j++; k=i;  
 }  
 for (l=1; lj; l++)  
  pow = i;  
 return ((unsigned int)(i-1))pow((unsigned int)tot[k]);   
}  
  
int main() {  
unsigned int i;  
FILE  fin = fopen("fractii.in","r");  
FILE  fout = fopen("fractii.out","w");  
  
 fscanf(fin,%d,&n);  
 ciur();  
 tot[1]=1;  
 tot[0]=1;  
 for (i=2; i=n; i++) {  
  tot[i] = totient(i);  
  tot[0] += 2tot[i];  
 }  
 fprintf(fout,%lldn,tot[0]);  
 fclose(fin);  
 fclose(fout);  
 return 0;  
}