#include<iostream>
#include<fstream>

using namespace std;

int cmmdc(int x, int y) {
	int man;
	while(y!=0) {
		man = x%y;
		x=y;
		y=man;
	}
	return x;
}

int main() {
	ifstream f("fractii.in");
	ofstream g("fractii.out");

	int n,p=1,q=1,s=0;
	f>>n; f.close();
	for(;;) {
		if(p<=n) {
			if(p==1 || q==1 || cmmdc(p,q)==1) { 
				s++; 
				if(q<n) q++;
				else {
					p++;
					q=1;
					continue;
				}
			}
			else {
				if(q<n) q++;
				else {
					p++;
					q=1;
					continue;
				}
			}

		}
		else break;
	}
	g<<s; g.close();
	return 0;
}