#include <stdio.h>

int cmmdc(int a,int b) {

	int i;
	for(i=2;i<=a&&i<=b;i++) {
		if(a%i==0&&b%i==0) {
			return 0;
		}
	}

	return 1;

}

int main() {
	FILE *f = fopen("fractii.in","rt");
	int n;
	fscanf(f,"%d",&n);

	int i,j;
	int contor = 0;

	for(i=1;i<=n;i++)
	{
		for(j=i+1;j<=n;j++) {
			if(cmmdc(i,j)==1)
				contor++;
		}
	}

	fclose(f);
	f = fopen("fractii.out","wt");
	fprintf(f,"%d",contor*2+1);

	return 0;
}