#include <stdio.h>   
FILE *f,*g;   
long cp,cq,p,q,n,contor=0;   
int main() {   
f=fopen("fractii.in" , "r");   
g=fopen("fractii.out" , "w");   
fscanf(f, "%ld" , &n);   
fclose(f);   
for(p=1;p<n;p++)    
        for(q=p+1;q<=n;q++){ cp=p; cq=q;   
            while(cp!=cq)if(cp>cq) cp=cp-cq;   
                            else cq=cq-cp;   
            if(cp==1) contor++; }   
fprintf(g, "%ld", contor*2);
fclose(g);   
return(0);   
}