# include <stdio.h>
# include <stdlib.h>


int N,result=1;
int cmmdc(int,int);

int main (){
	FILE *in=fopen("fractii.in","r");
	fscanf(in,"%d",&N);
	fclose(in);
	int i,j;
	for (i=2;i<=N;i++)
		for (j=1;j<i;j++)
			if(cmmdc(i,j)==1)
					result+=2;
	;
	
	FILE *out=fopen("fractii.out","w");
	fprintf(out,"%d",result);
	fclose(out);
	return 0;
}


int cmmdc ( int a,int b){
	if(a==0) 
		return b;
	if(b==0) 
		return a;
	if(a>b) 
		return cmmdc(a-b,b);
	return cmmdc(b-a,a);
}