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

int cmmdc(int a, int b){

	while(a != b){
		if(a >= b) {
			a = a - b;
		} else {
			b = b - a;
		}
	}

	return a;
}

int main(){

	FILE *fp, *fr;
	int a, result = 0, i, j;

	fp = fopen("fractii.in","r");
	fr = fopen("fractii.out", "w");

	fscanf(fp, "%d\n", &a);

	for(i = 1; i < a; i++){
		for(j = i + 1; j <= a; j++){
			if(cmmdc(i,j) == 1){
				result += 2;
			}
		}
	}
	result++;
	fprintf(fr, "%d", result);


	fclose(fp);
	fclose(fr);

	return 0;
}