#include<stdio.h>
long long gcd(long long a, long long b) {
	long long r;
	while (b != 0) {
		r = a % b;
		a = b;
		b = r;
	}
	return a;
}
int main() {
	FILE* input=fopen("fractii.in","r");
	FILE* output = fopen("fractii.out", "w");
	long long  N;
	long long fractii = 0;
	fscanf(input, "%lld", &N);
	if (N == 1)
		fprintf(output, "1");
	else {
		fractii++;
		for (long long i = 1; i < N; i++)
			for (long long j = i+1; j <= N; j++) {
				if (gcd(i, j) == 1)
					fractii+=2;
			}
	}
	fprintf(output, "%lld", fractii);
	return 0;
}