#include <cstdio>
#include <cmath>

long max(long a, long b) {
	if (a>b) return a;
	else return b;
}
long min(long a, long b) {
	if (a<b) return a;
	else return b;
}

bool ok(long a, long b) {
	bool t = true;
	for (int i = 2;i<=floor(sqrt(max(a,b)));i++) {
		if (a % i == 0 && b % i == 0) 
			return false;
	}
	return t;
}

int main() {
	FILE *f,*g;
	f = fopen("fractii.in","r");
	g = fopen("fractii.out","w");
	long int n,rez;
	fscanf(f,"%ld",&n);
	rez=0;
	for (long i=1;i<n;i++) {
		for (long j=i+1;j<=n;j++) {
			if (ok(i,j)) rez++;
		}
	}
	rez *= 2;
	rez++;
	
	fprintf(g,"%d",rez);
	
	
	fclose(f);
	fclose(g);
	return 0;
}