#include <stdio.h>

int main()
{
	int i, j, nr, sum = 0;
	FILE *f_in = fopen("fractii.in", "rt");
	FILE *f_out = fopen("fractii.out", "wt");
	fscanf(f_in, "%d", &nr);
	sum +=(nr*2)-1;
	int s=0;
	for(i=2 ; i<=nr ; i++)
		for(j=i; j<=nr ; j++)
			if( j%i==0 || i%j ==0)
				continue;
			else
				s++;
	fprintf(f_out, "%d", sum+2*s);
	fclose(f_in);
	fclose(f_out);
}