#include <stdio.h>
#include <math.h>

long n;

long gcd(long a, long b) {
	long c = 0;
	while (b != 0) {
		c = a % b;
		a = b;
		b = c;
	}
	return a;
}


int main() {
	freopen("fractii.in", "r", stdin);
	freopen("fractii.out", "w", stdout);
	scanf("%ld", &n);
	long i, j;
	long long sol = 0;
	long a, b, c;
	for (i = 1; i <= n; ++i) {
		for (j = i+1; j <= n; ++j) {
			a = i, b = j;
			while (b != 0) {
				c = a % b;
				a = b;
				b = c;
			}
			if (a == 1) ++sol;
		}
	}
	printf("%lld\n", sol * 2 + 1);
	return 0;
}