#include <stdio.h>
#define Nmax 1000001

int n, i, j, v[Nmax], S;

int main (){
	FILE * f = fopen ("fractii.in", "r");
	FILE * g = fopen ("fractii.out", "w");
	
	for (i = 2 ; i <= n ; i++)
		v[i] = i-1;
	for (i = 2 ; i <= n ; i++)
		for (j = 2*i ; j <= n ; j++)
			v[j] -= v[i];
		
	for (i = 2 ; i <= n ; i++)
		S = S + v[i];
	
	fprintf (g ,"%d", S);

	
	
	fclose(f);
	fclose(g);
	return 0;
}