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

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

int main() {
	FILE *in, *out;
	if (((in = fopen("fractii.in", "rt")) == NULL)) {
		printf("Nu am putut deschide fisierul de input!");
		return -1;
	}
	if (((out = fopen("fractii.out", "wt")) == NULL)) {
		printf("Nu am putut deschide fisierul de output!");
		return -2;
	}
	int i, j, n, sum = 0;
	fscanf(in, "%d", &n);
	for (i = 2 ; i <= n - 1 ; ++i) {
		for (j = i + 1 ; j <= n ; ++j) {
			if (cmmdc(i, j) == 1) {
				sum += 1;
			}
		}
	}
	sum *= 2;
	sum += 2 * n - 1;
	fprintf(out, "%d\n", sum);
	// Freeing the memory
	fclose(in);
	fclose(out);
	return 0;
}