# include <iostream>
# include <fstream>

bool cmmdc ( int, int ) ;

int main () {

	std :: ifstream f ("fractii.in");
	std :: ofstream g ("fractii.out");

	int N, nr;

	f >> N;
	nr = 0;

	for ( int i = 1; i < N; i ++ ) {
		for ( int j = i + 1; j <= N; j ++ ) {
			if ( cmmdc ( i, j ) == true ) {
				nr ++;
			}
		}	
	}

	g << nr * 2 + 1 << '\n';
	return 0;
}

bool cmmdc ( int a, int b ) {
	while ( a != b ) {
		if ( a > b ) {
			a -= b;
		} else {
			b -= a;
		}
	}

	if ( a == 1 ) {
		return true;
	}

	return false;
}