#include <stdio.h>
#include <fstream.h>
#include <math.h>
FILE *pf;
int nr;
int ireduc(long a,long b);
int  ireduc(long a,long b)
{long i;int t=1;int max;
max=(a>=b)?a:b;
for(i=2;i<=sqrt(max);i++)
if((b%i==0)&&(a%i==0)) t=0;
if ((a==b)&&(a!=1)&&(b!=1))t=0;
return t;
}
long  n;
main(void)
{pf=fopen("fractii.in","r");
long i,j;
fscanf(pf,"%ld",&n);

for(i=1;i<n+1;i++)
for (j=1;j<=sqrt(n+1);j++)
if (ireduc(i,j)) nr ++;

pf=fopen("fractii.out","w");
fprintf(pf,"%d",nr);
fclose(pf);
return 0;
}